«

On Tue, 17 Jul 2007 06:06:36 -0700, wrote:

>On Jul 17, 2:27 am, Whiskers <catwhee...@operamail.com> wrote:
>> On 2007-07-16, pawi...@yahoo.com <pawi...@yahoo.com> wrote:
>>
>> > This must be a dumb question, but can anyone please tell me what
>> > OHP paper is ?
>>
>> > What is its composition ?
>>
>> Not paper. Traditionally, "acetate" which is preferred for its flatness,
>> clarity, and neutral colour. I daresay other substances might be used too;
>> you'd have to inspect the packaging in the shop or contact various
>> suppliers or makers to get the specification of different products.
>>
>> > What are its heat resisting properties compared to cellophane,
>> > paper, etc. ?

<snip>

>> Some types have peel-off opaque or translucent backing, possibly marked
>> with lines or a grid to assist layout. The pacakaging should include
>> instructions for use and handling to get best results for the purpose the
>> stuff is sold for. 'Non stick' would seem to conflict with the need for
>> it to retain what you draw or print on it.
>>
>
>Thanks, that's the kind of reply I hoped for. Not like those that
>treat my post as if I was asking for classified information that
>was meant to be dispensed sparingly on a need-to-know basis.
>
>My reason for asking was as follows (I just didn't think I'd need
>to post it to ask what I thought were straightforward questions):

How? You didn't ask what you really wanted until this post. You skipped
over the real question.

>Someone asked in a forum how to make PCBs, and someone else
>claimed that he uses OHP paper as an iron-on medium to transfer
>the copper track design on to the raw copper-clad board.

Then a whole lot of the question seems pointless. A more direct answer
could have been more forthcoming if you mentioned the really simple
request at the beginning. Your 1st post could have just mentioned OHP
film, PCBs. Only a paragraph was required.

Used OHP film for years, but always UV etching, never used any iron-on
method.

<snip>

Not knowing the source of the info, have you (a more pointed response
since you now mention the real topic) -

These newsgroups,
All groups > USENET > sci . electronics clear
Usenet 1 - 9 of 9

sci.electronics
sci.electronics.basic
sci.electronics.basics
sci.electronics.cad
sci.electronics.components.* (1)
sci.electronics.design
sci.electronics.equipment.* (1)
sci.electronics.misc.* (1)
sci.electronics.repair.* (1)


>Another reason for framing my questions as I did is that I like
>to collect as much info as possible on any topic I'm interested
>in, including extraneous tidbits that may not be immediately
>relevant. Such pieces of info have often proved to be very useful
>later.

Then expect the generic answers you got. Ask a more direct question and
use the info to then do your own research for higher level of detail.

Me

wrote:
Subject: Re: What is OHP paper ?

>>> This must be a dumb question, but can anyone please tell me what
>>> OHP paper is ?

> Someone asked in a forum how to make PCBs, and someone else
> claimed that he uses OHP paper as an iron-on medium to transfer
> the copper track design on to the raw copper-clad board.

Not OHP paper. OHP *film*. If you search on OHP PCB you will find
plenty of discussions including discussions of those who prefer other
'printing' surfaces over OHP film. However, if you search on OHP paper
PCB, you get virtually nothing, of course.

> Another reason for framing my questions as I did is that I like
> to collect as much info as possible on any topic I'm interested
> in, including extraneous tidbits that may not be immediately
> relevant.

You did a very bad job of framing your question. Your question was
about making a PCB, which fact wasn't even mentioned. You should start
with the target, what you are trying to do and then narrow it to ask
'what about using PCB film?' to do it -- and most importantly you
shouldn't put a 'bad' or errant term into your inadequate question,
namely 'paper'. The term paper is very confusing to the issue of
overhead projecting -- and it is especially confusing in light of the
fact that you had no interest in overhead projecting.

--
Mike Easter

On Jul 17, 10:07 pm, "Mike Easter" <Mi...@ster.invalid> wrote:
> pawi...@yahoo.com wrote:
>
> Subject: Re: What is OHP paper ?
>
> >>> This must be a dumb question, but can anyone please tell me what
> >>> OHP paper is ?
> > Someone asked in a forum how to make PCBs, and someone else
> > claimed that he uses OHP paper as an iron-on medium to transfer
> > the copper track design on to the raw copper-clad board.
>
> Not OHP paper. OHP *film*. If you search on OHP PCB you will find
> plenty of discussions including discussions of those who prefer other
> 'printing' surfaces over OHP film. However, if you search on OHP paper
> PCB, you get virtually nothing, of course.
>
> > Another reason for framing my questions as I did is that I like
> > to collect as much info as possible on any topic I'm interested
> > in, including extraneous tidbits that may not be immediately
> > relevant.
>
> You did a very bad job of framing your question. Your question was
> about making a PCB, which fact wasn't even mentioned. You should start
> with the target, what you are trying to do and then narrow it to ask
> 'what about using PCB film?' to do it -- and most importantly you
> shouldn't put a 'bad' or errant term into your inadequate question,
> namely 'paper'. The term paper is very confusing to the issue of
> overhead projecting -- and it is especially confusing in light of the
> fact that you had no interest in overhead projecting.
>
I appreciate the replies, and I bow to the consensus that I did
not ask my questions properly - without fully understanding why.
If someone else had asked the same questions, knowing what I do
now, I'd answer with something like this (even if I had no idea
what the OP wanted it for) -

OHP = Overhead Projector, and it's film, not paper.
It's usually made of cellulose acetate.
The usual OHP film is much less resistant to heat than paper.
It's not particularly stick-resistant, at least not to the same
degree as material specifically made to be so, such as sticker
backings or release paper. I don't know if there are any special
types with non-stick coating.

These answers address each of my initial questions in a few
sentences. It's not as if I asked "I want to buy a digital
camera. Which one should I buy ?" or "My computer won't start.
What can be wrong ?" without giving any other info.

I really did not mean to ask for opinions on whether OHP film/
paper is suitable for making PCBs. I thought I'd obtain basic
information about the material's properties and make up my own
mind. BTW, I said "OHP *paper*" because the poster said "OHP
paper".