«

Hi,

I noticed something weird.
I converted a photo into grayscale in photoshop.
I tried to print the grayscale photo using a printer
with black ink enable only versus default.
There is difference between them. The
one where "black ink only" is NOT specified
produced more detailed greyish image. But
then isn't it that in grayscale image, it is
supposed to be made up of pure black and
white. How come the printer produced
different outputs if it uses all colors to print
the grayscale versus using entirely black
ink??

Mark

Mark Franzels wrote:
> Hi,
>
> I noticed something weird.
> I converted a photo into grayscale in photoshop.
> I tried to print the grayscale photo using a printer
> with black ink enable only versus default.
> There is difference between them. The
> one where "black ink only" is NOT specified
> produced more detailed greyish image. But
> then isn't it that in grayscale image, it is
> supposed to be made up of pure black and
> white. How come the printer produced
> different outputs if it uses all colors to print
> the grayscale versus using entirely black
> ink??
>
Most printers without dedicated monochrome ink in various "strengths"
use blends of coloured ink to produce lighter shades. It's critical
that the right amount of each colour is applied, or the print may have a
colour cast, and typically that colour cast will vary between dark and
light shades. That said, with care quite good results can be obtained
from some colour printers (but often the result is quite bad).
Printing just with "full strength" black only, then the printer can't
produce as much detail in lighter areas, as there are limits to minimum
droplet size and placement.
Printers with dedicated monochrome inks usually have three or more black
inks, usually called "light black" and "light light black" etc. The
higher end printers also usually have black ink which is as neutral as
possible, made with a little blue added to offset the brownish-yellow of
carbon black pigments. However, they still use a little coloured ink to
eliminate colour casts. There are some aftermarket inks to suit some
(usually higher end) printers, which are a full set (perhaps 8 shades)
of black cartridges.

In article <grppts$67g$>, Me <>
wrote:

> Mark Franzels wrote:
> > Hi,
> >
> > I noticed something weird.
> > I converted a photo into grayscale in photoshop.
> > I tried to print the grayscale photo using a printer
> > with black ink enable only versus default.
> > There is difference between them. The
> > one where "black ink only" is NOT specified
> > produced more detailed greyish image. But
> > then isn't it that in grayscale image, it is
> > supposed to be made up of pure black and
> > white. How come the printer produced
> > different outputs if it uses all colors to print
> > the grayscale versus using entirely black
> > ink??
> >
> Most printers without dedicated monochrome ink in various "strengths"
> use blends of coloured ink to produce lighter shades. It's critical
> that the right amount of each colour is applied, or the print may have a
> colour cast, and typically that colour cast will vary between dark and
> light shades. That said, with care quite good results can be obtained
> from some colour printers (but often the result is quite bad).
> Printing just with "full strength" black only, then the printer can't
> produce as much detail in lighter areas, as there are limits to minimum
> droplet size and placement.
> Printers with dedicated monochrome inks usually have three or more black
> inks, usually called "light black" and "light light black" etc. The
> higher end printers also usually have black ink which is as neutral as
> possible, made with a little blue added to offset the brownish-yellow of
> carbon black pigments. However, they still use a little coloured ink to
> eliminate colour casts. There are some aftermarket inks to suit some
> (usually higher end) printers, which are a full set (perhaps 8 shades)
> of black cartridges.


This has to get the prize for the response of the week!
Great answer, very informative and extremely well-written.

--
m-m
http://www.mhmyers.com

On Apr 11, 6:03*pm, Me <u...@domain.invalid> wrote:
> Mark Franzels wrote:
> > Hi,
>
> > I noticed something weird.
> > I converted a photo into grayscale in photoshop.
> > I tried to print the grayscale photo using a printer
> > with black ink enable only versus default.
> > There is difference between them. The
> > one where "black ink only" is NOT specified
> > produced more detailed greyish image. But
> > then isn't it that in grayscale image, it is
> > supposed to be made up of pure black and
> > white. How come the printer produced
> > different outputs if it uses all colors to print
> > the grayscale versus using entirely black
> > ink??
>
> Most printers without dedicated monochrome ink in various "strengths"
> use blends of coloured ink to produce lighter shades. *It's critical
> that the right amount of each colour is applied, or the print may have a
> colour cast, and typically that colour cast will vary between dark and
> light shades. *That said, with care quite good results can be obtained
> from some colour printers (but often the result is quite bad).
> Printing just with "full strength" black only, then the printer can't
> produce as much detail in lighter areas, as there are limits to minimum
> droplet size and placement.
> Printers with dedicated monochrome inks usually have three or more black
> inks, usually called "light black" and "light light black" etc. *The
> higher end printers also usually have black ink which is as neutral as
> possible, made with a little blue added to offset the brownish-yellow of

How about laser printers with black only toner. Do you
called it with black as neutral as possible? I just noticed
that using the same file in grayscale. The laser printer
prints it much better than an inkjet printer with setting
of "use black ink only". Why is that? It seems for
purely black output. The laser printer is more optimized
than an inkjet set at black ink only, agree? But why.
Thanks.

Mark

> carbon black pigments. *However, they still use a little coloured ink to
> eliminate colour casts. *There are some aftermarket inks to suit some
> (usually higher end) printers, which are a full set (perhaps 8 shades)
> of black cartridges.- Hide quoted text -
>
> - Show quoted text -

Mark Franzels wrote:
> On Apr 11, 6:03 pm, Me <u...@domain.invalid> wrote:
>> Mark Franzels wrote:
>>> Hi,
>>> I noticed something weird.
>>> I converted a photo into grayscale in photoshop.
>>> I tried to print the grayscale photo using a printer
>>> with black ink enable only versus default.
>>> There is difference between them. The
>>> one where "black ink only" is NOT specified
>>> produced more detailed greyish image. But
>>> then isn't it that in grayscale image, it is
>>> supposed to be made up of pure black and
>>> white. How come the printer produced
>>> different outputs if it uses all colors to print
>>> the grayscale versus using entirely black
>>> ink??
>> Most printers without dedicated monochrome ink in various "strengths"
>> use blends of coloured ink to produce lighter shades. It's critical
>> that the right amount of each colour is applied, or the print may have a
>> colour cast, and typically that colour cast will vary between dark and
>> light shades. That said, with care quite good results can be obtained
>> from some colour printers (but often the result is quite bad).
>> Printing just with "full strength" black only, then the printer can't
>> produce as much detail in lighter areas, as there are limits to minimum
>> droplet size and placement.
>> Printers with dedicated monochrome inks usually have three or more black
>> inks, usually called "light black" and "light light black" etc. The
>> higher end printers also usually have black ink which is as neutral as
>> possible, made with a little blue added to offset the brownish-yellow of
>
> How about laser printers with black only toner. Do you
> called it with black as neutral as possible? I just noticed
> that using the same file in grayscale. The laser printer
> prints it much better than an inkjet printer with setting
> of "use black ink only". Why is that? It seems for
> purely black output. The laser printer is more optimized
> than an inkjet set at black ink only, agree? But why.
> Thanks.
>
It probably varies between printer, but a laser optimised to use black
toner might be able to place toner more accurately than the inkjet.
If you've got a Canon inkjet, some models use dye inks for colour photo
printing, and a pigment ink for black for text only printing (more
waterproof and less prone to bleed than dye based ink on uncoated
papers). At a guess, when switched to black only, it's using the
pigment ink, and the nozzles/head used are probably not capable of
producing small droplet sizes, or the printer "assumes" text, where high
dpi isn't needed. The three main makers (Epson, Canon, and HP) use
significantly different methods to vary droplet size.

On Apr 12, 9:08*am, Me <u...@domain.invalid> wrote:
> Mark Franzels wrote:
> > On Apr 11, 6:03 pm, Me <u...@domain.invalid> wrote:
> >> Mark Franzels wrote:
> >>> Hi,
> >>> I noticed something weird.
> >>> I converted a photo into grayscale in photoshop.
> >>> I tried to print the grayscale photo using a printer
> >>> with black ink enable only versus default.
> >>> There is difference between them. The
> >>> one where "black ink only" is NOT specified
> >>> produced more detailed greyish image. But
> >>> then isn't it that in grayscale image, it is
> >>> supposed to be made up of pure black and
> >>> white. How come the printer produced
> >>> different outputs if it uses all colors to print
> >>> the grayscale versus using entirely black
> >>> ink??
> >> Most printers without dedicated monochrome ink in various "strengths"
> >> use blends of coloured ink to produce lighter shades. *It's critical
> >> that the right amount of each colour is applied, or the print may have a
> >> colour cast, and typically that colour cast will vary between dark and
> >> light shades. *That said, with care quite good results can be obtained
> >> from some colour printers (but often the result is quite bad).
> >> Printing just with "full strength" black only, then the printer can't
> >> produce as much detail in lighter areas, as there are limits to minimum
> >> droplet size and placement.
> >> Printers with dedicated monochrome inks usually have three or more black
> >> inks, usually called "light black" and "light light black" etc. *The
> >> higher end printers also usually have black ink which is as neutral as
> >> possible, made with a little blue added to offset the brownish-yellow of
>
> > How about laser printers with black only toner. Do you
> > called it with black as neutral as possible? I just noticed
> > that using the same file in grayscale. The laser printer
> > prints it much better than an inkjet printer with setting
> > of "use black ink only". Why is that? It seems for
> > purely black output. The laser printer is more optimized
> > than an inkjet set at black ink only, agree? But why.
> > Thanks.
>
> It probably varies between printer, but a laser optimised to use black
> toner might be able to place toner more accurately than the inkjet.
> If you've got a Canon inkjet, some models use dye inks for colour photo
> printing, and a pigment ink for black for text only printing (more
> waterproof and less prone to bleed than dye based ink on uncoated
> papers). *At a guess, when switched to black only, it's using the
> pigment ink, and the nozzles/head used are probably not capable of
> producing small droplet sizes, or the printer "assumes" text, where high
> dpi isn't needed. *The three main makers (Epson, Canon, and HP) use
> significantly different methods to vary droplet size.- Hide quoted text -
>
> - Show quoted text -

It's an HP specifically HP Deskjet 910 with the most
cheapest ink.. the black cartridge is model HP CB314
that only costs $5 and it can print up to 500 pages.
So I guess the nozzles are made gross? What can
you say about other HP cartridges especially
black, does it use pigments or dye? How can I
know what it is? Why, when you use normal
inkjets and set the ink to print in black cartridge
only, is it supposed to produce grayscale the
same shades as that of dedicated monochrome
laser printers?

On Apr 12, 6:22*am, Mark Franzels <markfranz...@gmail.com> wrote:
> On Apr 12, 9:08*am, Me <u...@domain.invalid> wrote:
>
>
>
> > Mark Franzels wrote:
> > > On Apr 11, 6:03 pm, Me <u...@domain.invalid> wrote:
> > >> Mark Franzels wrote:
> > >>> Hi,
> > >>> I noticed something weird.
> > >>> I converted a photo into grayscale in photoshop.
> > >>> I tried to print the grayscale photo using a printer
> > >>> with black ink enable only versus default.
> > >>> There is difference between them. The
> > >>> one where "black ink only" is NOT specified
> > >>> produced more detailed greyish image. But
> > >>> then isn't it that in grayscale image, it is
> > >>> supposed to be made up of pure black and
> > >>> white. How come the printer produced
> > >>> different outputs if it uses all colors to print
> > >>> the grayscale versus using entirely black
> > >>> ink??
> > >> Most printers without dedicated monochrome ink in various "strengths"
> > >> use blends of coloured ink to produce lighter shades. *It's critical
> > >> that the right amount of each colour is applied, or the print may have a
> > >> colour cast, and typically that colour cast will vary between dark and
> > >> light shades. *That said, with care quite good results can be obtained
> > >> from some colour printers (but often the result is quite bad).
> > >> Printing just with "full strength" black only, then the printer can't
> > >> produce as much detail in lighter areas, as there are limits to minimum
> > >> droplet size and placement.
> > >> Printers with dedicated monochrome inks usually have three or more black
> > >> inks, usually called "light black" and "light light black" etc. *The
> > >> higher end printers also usually have black ink which is as neutral as
> > >> possible, made with a little blue added to offset the brownish-yellow of
>
> > > How about laser printers with black only toner. Do you
> > > called it with black as neutral as possible? I just noticed
> > > that using the same file in grayscale. The laser printer
> > > prints it much better than an inkjet printer with setting
> > > of "use black ink only". Why is that? It seems for
> > > purely black output. The laser printer is more optimized
> > > than an inkjet set at black ink only, agree? But why.
> > > Thanks.
>
> > It probably varies between printer, but a laser optimised to use black
> > toner might be able to place toner more accurately than the inkjet.
> > If you've got a Canon inkjet, some models use dye inks for colour photo
> > printing, and a pigment ink for black for text only printing (more
> > waterproof and less prone to bleed than dye based ink on uncoated
> > papers). *At a guess, when switched to black only, it's using the
> > pigment ink, and the nozzles/head used are probably not capable of
> > producing small droplet sizes, or the printer "assumes" text, where high
> > dpi isn't needed. *The three main makers (Epson, Canon, and HP) use
> > significantly different methods to vary droplet size.- Hide quoted text -
>
> > - Show quoted text -
>
> It's an HP specifically HP Deskjet 910 with the most
> cheapest ink.. the black cartridge is model HP CB314
> that only costs $5 and it can print up to 500 pages.
> So I guess the nozzles are made gross? What can
> you say about other HP cartridges especially
> black, does it use pigments or dye? How can I
> know what it is? Why, when you use normal
> inkjets and set the ink to print in black cartridge
> only, is it supposed to produce grayscale the
> same shades as that of dedicated monochrome
> laser printers?

Actually, I think you have so many variable going on that you couldn't
find one good reason if you tried. For example, a black from an
inkjet on regular paper is nowhere near as black as a laser. Part of
it is that the laser puts down 100% color and the inkjet needs some
sort of carrier. Also, ink absorbs and laser does not. Then there's
the different reflective nature of the systems. It also probably has
something to do with putting down more/better material to absorb light
if you use colors as well as black.

On my color laser, it gives you the option to go one of thee ways: CMY
+K; K; or K overprint.

On Apr 12, 9:39*pm, Pat <gro...@artisticphotography.us> wrote:
> On Apr 12, 6:22*am, Mark Franzels <markfranz...@gmail.com> wrote:
>
>
>
>
>
> > On Apr 12, 9:08*am, Me <u...@domain.invalid> wrote:
>
> > > Mark Franzels wrote:
> > > > On Apr 11, 6:03 pm, Me <u...@domain.invalid> wrote:
> > > >> Mark Franzels wrote:
> > > >>> Hi,
> > > >>> I noticed something weird.
> > > >>> I converted a photo into grayscale in photoshop.
> > > >>> I tried to print the grayscale photo using a printer
> > > >>> with black ink enable only versus default.
> > > >>> There is difference between them. The
> > > >>> one where "black ink only" is NOT specified
> > > >>> produced more detailed greyish image. But
> > > >>> then isn't it that in grayscale image, it is
> > > >>> supposed to be made up of pure black and
> > > >>> white. How come the printer produced
> > > >>> different outputs if it uses all colors to print
> > > >>> the grayscale versus using entirely black
> > > >>> ink??
> > > >> Most printers without dedicated monochrome ink in various "strengths"
> > > >> use blends of coloured ink to produce lighter shades. *It's critical
> > > >> that the right amount of each colour is applied, or the print may have a
> > > >> colour cast, and typically that colour cast will vary between dark and
> > > >> light shades. *That said, with care quite good results can be obtained
> > > >> from some colour printers (but often the result is quite bad).
> > > >> Printing just with "full strength" black only, then the printer can't
> > > >> produce as much detail in lighter areas, as there are limits to minimum
> > > >> droplet size and placement.
> > > >> Printers with dedicated monochrome inks usually have three or more black
> > > >> inks, usually called "light black" and "light light black" etc. *The
> > > >> higher end printers also usually have black ink which is as neutral as
> > > >> possible, made with a little blue added to offset the brownish-yellow of
>
> > > > How about laser printers with black only toner. Do you
> > > > called it with black as neutral as possible? I just noticed
> > > > that using the same file in grayscale. The laser printer
> > > > prints it much better than an inkjet printer with setting
> > > > of "use black ink only". Why is that? It seems for
> > > > purely black output. The laser printer is more optimized
> > > > than an inkjet set at black ink only, agree? But why.
> > > > Thanks.
>
> > > It probably varies between printer, but a laser optimised to use black
> > > toner might be able to place toner more accurately than the inkjet.
> > > If you've got a Canon inkjet, some models use dye inks for colour photo
> > > printing, and a pigment ink for black for text only printing (more
> > > waterproof and less prone to bleed than dye based ink on uncoated
> > > papers). *At a guess, when switched to black only, it's using the
> > > pigment ink, and the nozzles/head used are probably not capable of
> > > producing small droplet sizes, or the printer "assumes" text, where high
> > > dpi isn't needed. *The three main makers (Epson, Canon, and HP) use
> > > significantly different methods to vary droplet size.- Hide quoted text -
>
> > > - Show quoted text -
>
> > It's an HP specifically HP Deskjet 910 with the most
> > cheapest ink.. the black cartridge is model HP CB314
> > that only costs $5 and it can print up to 500 pages.
> > So I guess the nozzles are made gross? What can
> > you say about other HP cartridges especially
> > black, does it use pigments or dye? How can I
> > know what it is? Why, when you use normal
> > inkjets and set the ink to print in black cartridge
> > only, is it supposed to produce grayscale the
> > same shades as that of dedicated monochrome
> > laser printers?
>
> Actually, I think you have so many variable going on that you couldn't
> find one good reason if you tried. *For example, a black from an
> inkjet on regular paper is nowhere near as black as a laser. *Part of
> it is that the laser puts down 100% color and the inkjet needs some
> sort of carrier. Also, ink absorbs and laser does not. *Then there's

What carrier are you talking about and what has it got to do
with inkjet printing?

> the different reflective nature of the systems. *It also probably has
> something to do with putting down more/better material to absorb light
> if you use colors as well as black.

What more/better material to absorb light? Do you mean
the printed output or something inside the printer?

I think it has to do with marketing stragegy too. If people can
just use black to print grayscale, their color cartridge
may not sell like pancakes.. instead they design the printers
in such a way that most of the time you need color to
print some black shade. When I printed in purely blank
ink, all the subtle shadings are not printed, even pure
text from a magazine in PDF is not printed black, but
very faded black, so even if printing a normal black fonts.
The manufacturers make sure the colors would be used
so they can earn profit from it.

All HP inks have heads on the the cartridge right? Mabye
the nozzles in my HP blank ink cartridge are only low
res, that's why it is very cheap at $5 and can
supposedly print 500 pages... what it doesn't tell
you is 500 pages of very faded text that can give
you severe eyestrain just by reading it. I wonder
what about those more expensive HP black in
cartridge.. do they print the subtle shadings well.
(note: If anyone has experience in printing HP
black ink only and comparing the output to
the laser, let me know. Thanks.)

Mark

>
> On my color laser, it gives you the option to go one of thee ways: CMY
> +K; K; or K overprint.- Hide quoted text -
>
> - Show quoted text -

Mark Franzels wrote:
> On Apr 12, 9:08 am, Me <u...@domain.invalid> wrote:
>> Mark Franzels wrote:
>>> On Apr 11, 6:03 pm, Me <u...@domain.invalid> wrote:
>>>> Mark Franzels wrote:
>>>>> Hi,
>>>>> I noticed something weird.
>>>>> I converted a photo into grayscale in photoshop.
>>>>> I tried to print the grayscale photo using a printer
>>>>> with black ink enable only versus default.
>>>>> There is difference between them. The
>>>>> one where "black ink only" is NOT specified
>>>>> produced more detailed greyish image. But
>>>>> then isn't it that in grayscale image, it is
>>>>> supposed to be made up of pure black and
>>>>> white. How come the printer produced
>>>>> different outputs if it uses all colors to print
>>>>> the grayscale versus using entirely black
>>>>> ink??
>>>> Most printers without dedicated monochrome ink in various "strengths"
>>>> use blends of coloured ink to produce lighter shades. It's critical
>>>> that the right amount of each colour is applied, or the print may have a
>>>> colour cast, and typically that colour cast will vary between dark and
>>>> light shades. That said, with care quite good results can be obtained
>>>> from some colour printers (but often the result is quite bad).
>>>> Printing just with "full strength" black only, then the printer can't
>>>> produce as much detail in lighter areas, as there are limits to minimum
>>>> droplet size and placement.
>>>> Printers with dedicated monochrome inks usually have three or more black
>>>> inks, usually called "light black" and "light light black" etc. The
>>>> higher end printers also usually have black ink which is as neutral as
>>>> possible, made with a little blue added to offset the brownish-yellow of
>>> How about laser printers with black only toner. Do you
>>> called it with black as neutral as possible? I just noticed
>>> that using the same file in grayscale. The laser printer
>>> prints it much better than an inkjet printer with setting
>>> of "use black ink only". Why is that? It seems for
>>> purely black output. The laser printer is more optimized
>>> than an inkjet set at black ink only, agree? But why.
>>> Thanks.
>> It probably varies between printer, but a laser optimised to use black
>> toner might be able to place toner more accurately than the inkjet.
>> If you've got a Canon inkjet, some models use dye inks for colour photo
>> printing, and a pigment ink for black for text only printing (more
>> waterproof and less prone to bleed than dye based ink on uncoated
>> papers). At a guess, when switched to black only, it's using the
>> pigment ink, and the nozzles/head used are probably not capable of
>> producing small droplet sizes, or the printer "assumes" text, where high
>> dpi isn't needed. The three main makers (Epson, Canon, and HP) use
>> significantly different methods to vary droplet size.- Hide quoted text -
>>
>> - Show quoted text -
>
> It's an HP specifically HP Deskjet 910 with the most
> cheapest ink.. the black cartridge is model HP CB314
> that only costs $5 and it can print up to 500 pages.
> So I guess the nozzles are made gross? What can
> you say about other HP cartridges especially
> black, does it use pigments or dye?
I think those cartridges are all dye based ink. That is a printer from
the mid-late 1990s ? HP used to make some reliable gear.
IIRC I had a Deskjet 910 printer years ago, and when printing in
greyscale, it used a very coarse raster pattern for half tones. I think
that more modern inkjets will be quite different.
For photo printing (colour), those old printers have truly terrible
print fading problems, as well as zero water resistance.


> How can I
> know what it is? Why, when you use normal
> inkjets and set the ink to print in black cartridge
> only, is it supposed to produce grayscale the
> same shades as that of dedicated monochrome
> laser printers?
>

On Apr 12, 10:24*am, Mark Franzels <markfranz...@gmail.com> wrote:
> On Apr 12, 9:39*pm, Pat <gro...@artisticphotography.us> wrote:
>
>
>
> > On Apr 12, 6:22*am, Mark Franzels <markfranz...@gmail.com> wrote:
>
> > > On Apr 12, 9:08*am, Me <u...@domain.invalid> wrote:
>
> > > > Mark Franzels wrote:
> > > > > On Apr 11, 6:03 pm, Me <u...@domain.invalid> wrote:
> > > > >> Mark Franzels wrote:
> > > > >>> Hi,
> > > > >>> I noticed something weird.
> > > > >>> I converted a photo into grayscale in photoshop.
> > > > >>> I tried to print the grayscale photo using a printer
> > > > >>> with black ink enable only versus default.
> > > > >>> There is difference between them. The
> > > > >>> one where "black ink only" is NOT specified
> > > > >>> produced more detailed greyish image. But
> > > > >>> then isn't it that in grayscale image, it is
> > > > >>> supposed to be made up of pure black and
> > > > >>> white. How come the printer produced
> > > > >>> different outputs if it uses all colors to print
> > > > >>> the grayscale versus using entirely black
> > > > >>> ink??
> > > > >> Most printers without dedicated monochrome ink in various "strengths"
> > > > >> use blends of coloured ink to produce lighter shades. *It's critical
> > > > >> that the right amount of each colour is applied, or the print may have a
> > > > >> colour cast, and typically that colour cast will vary between dark and
> > > > >> light shades. *That said, with care quite good results can be obtained
> > > > >> from some colour printers (but often the result is quite bad).
> > > > >> Printing just with "full strength" black only, then the printer can't
> > > > >> produce as much detail in lighter areas, as there are limits to minimum
> > > > >> droplet size and placement.
> > > > >> Printers with dedicated monochrome inks usually have three or more black
> > > > >> inks, usually called "light black" and "light light black" etc. *The
> > > > >> higher end printers also usually have black ink which is as neutral as
> > > > >> possible, made with a little blue added to offset the brownish-yellow of
>
> > > > > How about laser printers with black only toner. Do you
> > > > > called it with black as neutral as possible? I just noticed
> > > > > that using the same file in grayscale. The laser printer
> > > > > prints it much better than an inkjet printer with setting
> > > > > of "use black ink only". Why is that? It seems for
> > > > > purely black output. The laser printer is more optimized
> > > > > than an inkjet set at black ink only, agree? But why.
> > > > > Thanks.
>
> > > > It probably varies between printer, but a laser optimised to use black
> > > > toner might be able to place toner more accurately than the inkjet.
> > > > If you've got a Canon inkjet, some models use dye inks for colour photo
> > > > printing, and a pigment ink for black for text only printing (more
> > > > waterproof and less prone to bleed than dye based ink on uncoated
> > > > papers). *At a guess, when switched to black only, it's using the
> > > > pigment ink, and the nozzles/head used are probably not capable of
> > > > producing small droplet sizes, or the printer "assumes" text, where high
> > > > dpi isn't needed. *The three main makers (Epson, Canon, and HP) use
> > > > significantly different methods to vary droplet size.- Hide quoted text -
>
> > > > - Show quoted text -
>
> > > It's an HP specifically HP Deskjet 910 with the most
> > > cheapest ink.. the black cartridge is model HP CB314
> > > that only costs $5 and it can print up to 500 pages.
> > > So I guess the nozzles are made gross? What can
> > > you say about other HP cartridges especially
> > > black, does it use pigments or dye? How can I
> > > know what it is? Why, when you use normal
> > > inkjets and set the ink to print in black cartridge
> > > only, is it supposed to produce grayscale the
> > > same shades as that of dedicated monochrome
> > > laser printers?
>
> > Actually, I think you have so many variable going on that you couldn't
> > find one good reason if you tried. *For example, a black from an
> > inkjet on regular paper is nowhere near as black as a laser. *Part of
> > it is that the laser puts down 100% color and the inkjet needs some
> > sort of carrier. Also, ink absorbs and laser does not. *Then there's
>
> What carrier are you talking about and what has it got to do
> with inkjet printing?

An inkjet uses ink. The pigment needs a carrier -- usually water --
to get it onto the paper. That then either evaporates off or absorbs
in (or both). It goes into the paper whereas a laser is bonded to the
surface and doesn't absorb.

>
> > the different reflective nature of the systems. *It also probably has
> > something to do with putting down more/better material to absorb light
> > if you use colors as well as black.
>
> What more/better material to absorb light? Do you mean
> the printed output or something inside the printer?

Vision is reflected light. White is all of the colors in more or less
the same quantity. Black is not a color. Black is where all light is
absorbed. A thin later of ink/paint/anything might let light reflect
off of the surface below it. Then it won't look as black as denser
layer of ink might. That's why when an inkjet starts to run out of
color, for the first little bit the color looks lighter (and then
disappears).

If you use colored ink as well as black, you are putting down more
material to absorb light.

>
> I think it has to do with marketing stragegy too. If people can
> just use black to print grayscale, their color cartridge
> may not sell like pancakes.. instead they design the printers
> in such a way that most of the time you need color to
> print some black shade. When I printed in purely blank
> ink, all the subtle shadings are not printed, even pure
> text from a magazine in PDF is not printed black, but
> very faded black, so even if printing a normal black fonts.
> The manufacturers make sure the colors would be used
> so they can earn profit from it.
>
> All HP inks have heads on the the cartridge right? Mabye
> the nozzles in my HP blank ink cartridge are only low
> res, that's why it is very cheap at $5 and can
> supposedly print 500 pages... what it doesn't tell
> you is 500 pages of very faded text that can give
> you severe eyestrain just by reading it. I wonder
> what about those more expensive HP black in
> cartridge.. do they print the subtle shadings well.
> (note: If anyone has experience in printing HP
> black ink only and comparing the output to
> the laser, let me know. Thanks.)

I don't think inkjets are a dark and if you use cheap paper, they are
no wheres nears as sharp.

I used to use a black-only inkjet -- the Deskjet 500. IIRC it did
okay but you would be comparing it to dot-matrix at the time. Back
then, a lot of photocopiers weren't all that hot, either.

To test your printer hypothesis, just wait for a color cartridge to
get low. The design something that is solid color red, blue, and
yellow -- say a third of a sheet each. Just run it until you run out
of ink on all colors. Then try printing some black text. That will
show you what the black ink is doing.

>
> Mark
>
>
>
> > On my color laser, it gives you the option to go one of thee ways: CMY
> > +K; K; or K overprint.- Hide quoted text -
>
> > - Show quoted text -