Alan Townsend
12-Jul-2023, 10:52
Anyone who makes carbon or oil prints using swollen gelatin knows how deep the relief is after a lengthy soak in water. I figured out ways to preserve that depth in a carbon or pigment print by casting a mold of that depth, which is later filled with glop and allowed to dry. At least 1/16 or more of depth is possible.
About 30 years ago I was experimenting with oil printing, coated a sheet of matte mylar with a thick dichromated gelatin layer by free hand pouring. I always mixed gelatin and dichromate in small batches, like 50-100 ml and added the dichromate before pouring. After exposure, I soaked 5 by 6 sheet in water for a few hours and found the incredibly thick relief image we've all seen.
I rushed to town and bought a bag of plaster of Paris. When I returned home, the gelatin had dried out, so I returned it to a water overnight. The next morning, I mixed about a cup of plaster and poured it over the surface of the raised gelatin relief on a sheet of glass and let that sit for about 24 hours. When I removed the film from the plaster cast, the relieve was preserved with only a few pieces of plaster sticking to the gelatin. So I repeated the soak with dish detergent added and cast in two pours with some hardware cloth in between for more strength. This one came out perfect. Plaster is porous. By waiting for the swolen gelatin to dry again through the plaster, it shrinks slowly and does not adhere. In this way, a swollen gelatin can be reused several times.
Seeing this image depth in plaster is kind of amazing really. Next, I wanted to pour some sugar free glop into that female plaster casting, but knew it would run through the pores, so needed to seal them somehow. I got my can of KILZ primer, watered it down, and using a small artist brush, carefully brushed it inside the casting as thin as possible, and let that dry.
I mixed gelatin and black watercolor tube pigment and poured it into the primed and leveled casting, then took a small sheet of glass that was covered with waxed paper and carefully laid it on top. I put my plaster and glop sandwich in the fridge for a few hours, then carefully peeled away the waxed paper, and had a flat carbon print that didn't enough density but looked OK. After drying, I had my first really deep relief carbon print! It was really cool, but of course heavy and fragile. These would make nice little desk objects, but not wall hangable art.
The next phase was making silicon rubber molds of the gelatin relief using a mixture of silicone caulking and mineral spirits that was pourable. I could also have used castable silicon mold making material but would have needed to wait a long time to get it. I also tried latex rubber, which didn't work as well. When making a mold of the swollen gelatin, it needs to be made from a negative instead of a positive. I planned on casting these molts with polyester resin, which would be reinforced with fiberglass. I believe polyester resin could be cast directly against the swollen gelatin, but not sure of the effects of the moisture. A gel type of polyester should be used which includes a mold release and white pigment. This would be strong and light enough to hang on the wall.
Art curators may be slow to accept cured polyester resin as archival, but it lasts at least 20 years on boats parked out in the sun 24/7. On fabric covered aircraft, polyester fabric has replaced cotton. Cotton lasts about 10 years, polyester more like 20. Both are covered with materials that protect against the sun. Another argument for another day.
That about it. There are likely many other ways to cast that fleeting deep swollen gelatin. It's kind of like how the first Daguerreotype Artists saw color on their plates while developing, and then it disappeared. A physicist named Lippman (sp?) explained years later that this was an interference effect of light, which was demonstrated in the "Lippman Hologram" which is a two-dimensional hologram of an image that can be made in dichromated gelatin with a mercury bath at its surface. Coincidently, boiling mercury was the developer for Daguerreotypes. Now we have three-dimensional carbon prints from casting swollen gelatin, so we could make a true hologram of that, or get a computer operated cnc vertical milling machine and use a tiny ball headed tool to care photos in three-dimensions in any material we like, although this would give less detail, but could be much deeper.
The ultra deep relief carbon castings do have limited resolution due to the mechanical strength of materials. The unique beauty is due to the increased apparent density range due to the hill and valley effect. When illuminated at a steep angle, the shadows go much deeper because they are in the shadows as well as being those shadows. I should have done something with this process but didn't. I also wouldn't be surprised if other have done something similar.
Have fun,
Alan Townsend
About 30 years ago I was experimenting with oil printing, coated a sheet of matte mylar with a thick dichromated gelatin layer by free hand pouring. I always mixed gelatin and dichromate in small batches, like 50-100 ml and added the dichromate before pouring. After exposure, I soaked 5 by 6 sheet in water for a few hours and found the incredibly thick relief image we've all seen.
I rushed to town and bought a bag of plaster of Paris. When I returned home, the gelatin had dried out, so I returned it to a water overnight. The next morning, I mixed about a cup of plaster and poured it over the surface of the raised gelatin relief on a sheet of glass and let that sit for about 24 hours. When I removed the film from the plaster cast, the relieve was preserved with only a few pieces of plaster sticking to the gelatin. So I repeated the soak with dish detergent added and cast in two pours with some hardware cloth in between for more strength. This one came out perfect. Plaster is porous. By waiting for the swolen gelatin to dry again through the plaster, it shrinks slowly and does not adhere. In this way, a swollen gelatin can be reused several times.
Seeing this image depth in plaster is kind of amazing really. Next, I wanted to pour some sugar free glop into that female plaster casting, but knew it would run through the pores, so needed to seal them somehow. I got my can of KILZ primer, watered it down, and using a small artist brush, carefully brushed it inside the casting as thin as possible, and let that dry.
I mixed gelatin and black watercolor tube pigment and poured it into the primed and leveled casting, then took a small sheet of glass that was covered with waxed paper and carefully laid it on top. I put my plaster and glop sandwich in the fridge for a few hours, then carefully peeled away the waxed paper, and had a flat carbon print that didn't enough density but looked OK. After drying, I had my first really deep relief carbon print! It was really cool, but of course heavy and fragile. These would make nice little desk objects, but not wall hangable art.
The next phase was making silicon rubber molds of the gelatin relief using a mixture of silicone caulking and mineral spirits that was pourable. I could also have used castable silicon mold making material but would have needed to wait a long time to get it. I also tried latex rubber, which didn't work as well. When making a mold of the swollen gelatin, it needs to be made from a negative instead of a positive. I planned on casting these molts with polyester resin, which would be reinforced with fiberglass. I believe polyester resin could be cast directly against the swollen gelatin, but not sure of the effects of the moisture. A gel type of polyester should be used which includes a mold release and white pigment. This would be strong and light enough to hang on the wall.
Art curators may be slow to accept cured polyester resin as archival, but it lasts at least 20 years on boats parked out in the sun 24/7. On fabric covered aircraft, polyester fabric has replaced cotton. Cotton lasts about 10 years, polyester more like 20. Both are covered with materials that protect against the sun. Another argument for another day.
That about it. There are likely many other ways to cast that fleeting deep swollen gelatin. It's kind of like how the first Daguerreotype Artists saw color on their plates while developing, and then it disappeared. A physicist named Lippman (sp?) explained years later that this was an interference effect of light, which was demonstrated in the "Lippman Hologram" which is a two-dimensional hologram of an image that can be made in dichromated gelatin with a mercury bath at its surface. Coincidently, boiling mercury was the developer for Daguerreotypes. Now we have three-dimensional carbon prints from casting swollen gelatin, so we could make a true hologram of that, or get a computer operated cnc vertical milling machine and use a tiny ball headed tool to care photos in three-dimensions in any material we like, although this would give less detail, but could be much deeper.
The ultra deep relief carbon castings do have limited resolution due to the mechanical strength of materials. The unique beauty is due to the increased apparent density range due to the hill and valley effect. When illuminated at a steep angle, the shadows go much deeper because they are in the shadows as well as being those shadows. I should have done something with this process but didn't. I also wouldn't be surprised if other have done something similar.
Have fun,
Alan Townsend