Digital BW, The Print

Hi I am interested in gum printing which is a non silver photographic process. In this variation on this process a mixture of gelatin and glucose colored with a watercolor pigment is exposed through a negative to shortwave ultraviolet light. The uv causes the gelatin glucose mixture to become insoluble in water, and by developing in warm water, a print is made. This printing technique makes a relatively short tonal range print and usually requires multiple printings to fully reproduce the tonal variations of a negative. It would be greatly advantageous for this process to eliminate the negative substrate, so that the negative could be printed directly on the gelatin surface. This inkjet negative would then dissolve during development . This eliminates the negative substrate which must be transparent to uv-c, which is the light given off by germicidal lamps. Uv-c transparent plastics are available but coating these plastics to accept an inkjet printed negative is not for the faint of heart. I use Topas, which is a polymer plastic film that is completely transparent to uv-c.

By printing the negative on the surface of the gelatin glucose mixture, the problem of smoothly coating the uv transparent plastic to accept inkjet negatives is eliminated and no vacuum frame is needed . The only obstacle to this approach is in the registration of the paper to the successive negative images so that the multiple negatives can be precisely registered to the previous printings on the piece of paper. Do you know of a type of printer that would allow multiple printings of negatives on pre existing images with each image precisely registered to the preexisting images?

Best Regards

James Fisher

You would need a flatbed printer for this with a vacuum bed that allowed for multiple print passes and single-channel type access.

However, ink is a very complex chemistry and is mostly made to be as archival as possible and to print on very specific coatings so I don’t think the chemistry would work. A UV flatbed would not dissolve because of the polymerization.

best,
Walker
R&D InkjetMall

> On Mar 28, 2016, at 7:31 AM, geoman4919@yahoo.com [DigitalBlackandWhiteThePrint] <DigitalBlackandWhiteThePrint@yahoogroups.com> wrote:
> 
> 
> Hi I am interested in gum printing  which is a non silver photographic process. In this variation on this process a mixture of gelatin and glucose colored with a watercolor pigment is exposed through a negative to shortwave ultraviolet light. The uv causes the gelatin glucose mixture to become insoluble in water, and by developing in warm water, a print is made. This printing technique makes a relatively short tonal range print and usually requires multiple printings to fully reproduce the tonal variations of a negative. It would be greatly advantageous for this process to eliminate the negative substrate, so that the negative could be printed directly on the gelatin surface. This inkjet negative would then dissolve during development . This eliminates the negative substrate which must be transparent to uv-c, which is the light given off by germicidal lamps. Uv-c transparent plastics are available but coating these plastics to accept an inkjet printed negative is not for the faint of heart. I use Topas, which is a polymer plastic film that is completely transparent to uv-c.
> 
> 
> 
> By printing the negative on the surface of the gelatin glucose mixture, the problem of smoothly coating the uv transparent plastic to accept inkjet negatives is eliminated and no vacuum frame is needed . The only obstacle to this approach is in the registration of the paper to the successive negative images so that the multiple negatives can be precisely registered to the previous printings on the piece of paper. Do you know of a type of printer that would allow multiple printings of negatives on pre existing images with each image precisely registered to the preexisting images?
> 
> 
> 
> 
> 
> Best Regards
> 
> 
> 
> James Fisher
> 
>  
> 
> 
> 
> 
> 
>