Drawing Grd Lines on Ground Glass

Can someone suggest a way of drawing grid lines on plain 8x10 ground glass?
I'd like something that would be reasonably stable (i.e. wouldn't just rub
off in use) but that also could be removed if a mistake was made. I guess I
could always use a Sharpie pen and a ruler but I'm not sure how stable
and/or removable a Sharpie would be, nor am I confident that I could get the
lines perfectly parallel that way. Seems to me I've seen suggestions to use
Photoshop to make the lines on a piece of clear film and then somehow attach
the film to the ground glass but I'm unclear on the details.

Not a sharpie, permanent ink in the rough?
Not me...

A mechanical pencil with softer lead (single
thinness size and darker) for the markings,
a small architect's T-square (cheap plastic)
for guiding the pencil and maybe metal ruler
for measuring.

I do suggest the T-square have an edge that
is flush with the surface rather than "stepped
up", because the "up" kind can allow [one] to
"slur" the line somewhat underneath it or
outward, which is no bueno.

You can also buy clear templates from:
http://stores.ebay.com/Aletta-Photographic
.... cheaply, you add it to [in] your glass
clips on the camera, outside the glass.

.... hope this helped,

Alex

"Jack" wrote:
Can someone suggest a way of drawing grid lines on plain 8x10 ground glass?

A pencil is the norm. Use a .3mm lead, holding the pencil vertically.
The pencil is applied to the ground side and so is protected from smudging.
If you are confident of your skill then a Rapidograph and India ink is
a better choice.

To keep lines parallel use a T-square, carpenters' square, drafting
triangle, drafting machine ...

The grid lines I know of are either silk screened to the back,
smooth surface, of the glass or are made as 'unetched' clear
grid lines on the ground side.

Another alternative is to apply thin black tape to either side. Art
supply stores should stock some.

If you want to use an overlay then I would suggest the line draw feature
in a word processing, spread sheet or CAD program. Photoshop lines are
neither precise nor accurate. Attach the overlay to the smooth side
of the glass, printed side towards the glass.

Precision optical overlays that I am familiar with were made from
lithographic negatives. Draw the artwork on a sheet of paper and
use the camera to photograph it's own grid overlay - you will have
to contact 'print' a positive film. Alternately, if you have a
friend who does printed circuit layout, he can have an
ultra-precise lithographic overlay made for you.

Heavy clear silicon grease works well for laminating plastic to glass.
You have to be very careful not to get air bubbles, though most can be
removed with a print/inking roller.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/

"Jack" wrote in message
...
Can someone suggest a way of drawing grid lines on plain
8x10 ground glass?
I'd like something that would be reasonably stable (i.e.
wouldn't just rub
off in use) but that also could be removed if a mistake
was made. I guess I
could always use a Sharpie pen and a ruler but I'm not
sure how stable
and/or removable a Sharpie would be, nor am I confident
that I could get the
lines perfectly parallel that way. Seems to me I've seen
suggestions to use
Photoshop to make the lines on a piece of clear film and
then somehow attach
the film to the ground glass but I'm unclear on the
details.


A Sharpie will work fine if the lines are fine enough for
you. The ink comes off with Isopropyl (rubbing) alcohol. I
just tried this on the ground side of a scap of GG to make
sure.


--
---
Richard Knoppow
Los Angeles, CA, USA