"Jack" <TeeMax DeleteThis @film.net> 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 nolindan DeleteThis @ix.netcom.com
Consulting Engineer: Electronics; Informatics; Photonics.
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/<!-- ~MESSAGE_AFTER~ -->
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