Normally, I pour the asphaltum directly onto the collodion surface. As long as there is an even coat, it will prevent any oxidation of the silver. I don't know that I would say the surface is hard, but it's not tacky either after airing out for a week. I put the paper backing on pictures I give to other people, but on my own I leave that off. Since I may not have extended time to air out, the paper comes in handy to keep fingerprints from being pressed into the backing.
Thanks for the reply. So far I have only done tintypes with the exception of just a couple ambrotypes on clear glass. The black glass seems great but I don't have a source for it. This looks like it works great also.
I would be leery of the the image self destructing in time, cracking and pulling off the collodion even if varnished. Asphaltum contains sulfur which tarnishes silver. Just a thought.
Instead of having brush marks, this will ensure a smooth asphaltum surface. Excellent!
Thanks for this. Just what I needed to know!
Nice job. Do you varnish the plate before you add the asphaltum?
Does the stuff you use get fully hard or does it stay somewhat rubbery?
Normally, I pour the asphaltum directly onto the collodion surface. As long as there is an even coat, it will prevent any oxidation of the silver. I don't know that I would say the surface is hard, but it's not tacky either after airing out for a week. I put the paper backing on pictures I give to other people, but on my own I leave that off. Since I may not have extended time to air out, the paper comes in handy to keep fingerprints from being pressed into the backing.
Thanks for the reply. So far I have only done tintypes with the exception of just a couple ambrotypes on clear glass. The black glass seems great but I don't have a source for it. This looks like it works great also.
I just used this for one of my ambrotypes. Its perfect and cheap. One quart should do hundred 8 x 10's at least.
I would be leery of the the image self destructing in time, cracking and pulling off the collodion even if varnished. Asphaltum contains sulfur which tarnishes silver. Just a thought.