U of S | Mailing List Archive | alt-photo-process-l | Re: Alt print on Glass?

Re: Alt print on Glass?

Carborundum is very hard and used for grinding tough stuff. You can buy a carborundum block to aid in the
sharpening of knives and it comes in various grits.
A quality sandpaper of fine (600 or slightly less) grit like that in a wet-or-dry type can give a slight texture
to glass. I use a grittier version to sand the edges of glass cut for framing photographs.
Also, you can purchase hydrofluoric acid (of course wear gloves and eye protection as well as a high quality
mask if you work indoors) to etch glass.
Jack F

On May 18, 2009, at 8:30 PM, Jacek Gonsalves wrote:

Hi Tom,

Thanks for the information. Can you elaborate more on carborundum? Is there a specific product I can get? Is it this by any chance?

Ammonium to clean glass, will try some Windex, that i'm sure has ammonia in it ! :)

Quoting Tom Sobota <tom@sobota.net>:


Printing on glass is not very difficult but the exact procedure depends
on the process.
I have made three-color gums on glass, but gum doesn't stick very well
on plain glass, so I first 'frosted' the glass surface with
carborundum. Well, actually a valve-polishing compound that has

I use carborundum because just 'sanding' the glass is, in my
experience, very slow.

On the other hand, gelatin sticks to clean plain glass very well, so
any gelatin based process such as carbon works very well without the
need of any additional substrate. But the glass has to be VERY clean,
and that means at least some ammonia-based detergent. You could also
consult instructions for preparing glass for collodion. Glass is
notoriously difficult to clean well :-)

For maximum adherence of gelatin you could use some sodium silicate
substrate as used for collotype. However, for a quick test a reasonably
clean glass will do.

You don't need to brush the gelatin on the glass. Just flow it from a
flask, and help to spread it with a finger (or a glass rod). The
gelatin will dry to a nice transparent thin coat. Keep the glass warm
while spreading, and then cool it on a very level surface.

Tom Sobota
Madrid, Spain