Paging Sandy King, Paging Sandy King,....Help!!!!!

[Jorge]

Ok Sandy, I read your chapter in Comming into Focus about Carbon printing. So I tried to make the pigment tissue, well actually I had some 12x20 fil UPS messed up and I just removed the gelating and tried to use that as backing.

Now my question is, how thick should be the gelatin? I used a 10% Knox gelatin solution with 4 ml of glycerin and about 4 grams of watercolor pigment. Well, the darn thing ran all over the place, it was like trying to coat with water..lol...even my dog got gelatin on her hair....

I know it probably is hard to explain in words, but do you have a method to know how thick should I make the solution, should I try a 20%solution when using knox?

 

[Aggie]

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[Eric Rose]

Aggie your even more twisted than I thought!

 

[Jorge]

Jorge, I have this picture in my head of you and the taco bell dog stuck in a wigling mass of jello.

LOL....

 

[sanking]

Jorge,

A 10% gelatin solution, made with Knox gelatin, should be plenty thick enough. I use a similar gelatin and coat with an even thinner mixture, about 8%, and it coats very well at room temperature of around 70 degrees F, with the solution at about 95-100 degrees. Assuming the Knox is same as the one I have used (regular Knox food gelatin) a 10% solution should coat very well at 70 F.

It is possible that you broke the gelatin down by soaking it for too long in hot water. From time to time I have done this and in those circumstances the gelatin loses it ability to set.

Sandy

 

[sanking]

Jorge,

BTW, you really don't need to remove the gelatin of the film base. In fact, it is better not to because the dry tissue may just flake off plain polyester.

I use a material called Yupo for the tissue support. This is same as Kimdura, a synthetic plastic paper.

Sandy

 

[Jorge]

ah, perhaps I did let it soak too much or let it heat to much. I just wanted to make sure I was doing it right, I will give it a shot again. I think you are correct, this is much harder than pt/pd.

Thanks Sandy!

 

[Aggie]

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[sanking]

Jorge,

Since you believe there is the possbility that you may have kept the gelatin solution hot for too long let me further add that you do not want it ever to get over about 140F, not even for a few minutes, and certainly not for several hours. It would probably be ok to keep it warm overnight at a realatively low temperature, say at about 90-100 F, but really hot temperatures will break down the molecular structure quickly.

BTW, since the time of my chapter on carbon in Coming into Focus I have refined slightly my coating method. I now use a frame which I place over the paper to contain the warm gelatin solution and keep it from flowing off the paper. The frame I currently use is of magnetic sign material which i use over a piece of galvanized steel, but plain wooden frames will also work ok. You can see this technique by going to http://rmp.opusis.com/carbon/carbon.html, and I describ eit fully in my carbon manual which is sold through Bostick and Sullivan.

Sandy



Sandy

 

[Aggie]

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[Jorge]

Thanks Sandy, going back to my notes I did let it get too hot, I suppose I hydrolised the gelatin. That frame idea is excellent. I have not seen the link but I get your drift. That is one of those.."why didnt I think of that"....

Aggie the dog is bathed, she wants to do it again..lol...

 

[sanking]

Aggie,

Here is the link again. I may have cut and pasted an extra coma or period or something first time around.

http://rmp.opusis.com/carbon/carbon.html

Sandy

 

[Jorge]

Great Sandy, lots of good info in the link. Another question I had was how "dark" should the solution look, seeing the pics was great, I now have an idea what to look for. Thanks again for your great help and info.....

 

[sanking]

As a rough guide to how dark the pigmented solution should be, once you get it mixed up allow a drop or two to fall on a piece of plain white paper. It should be absolutely opaque, that is, you should not be able to see through the pigmented solution to the paper.

Pigments vary a lot in strength but if you are using tube watercolors I suspect that yoiu will need something on the order of 8-10g of pigment per liter of solution.

Sandy

 

[Jorge]

Thanks again Sandy, that is the way it looks in the pictures....it was a great help...BTW the sensitometric data you provide in the site is also a great help...saved me a lot of testing......

 

[sanking]

Jorge,

Just wondered if you were aware of the fact that Bostick and Sullivan will be offering carbon tissue for sale in the near future. Dick has been working on the coating procedures and apparatus for over two years. Says that I gave him the carbon virus with my carbon presentation at APIS two years ago. In any event I have been beta testing his tissue for some months now and it is almost ready for the market.

Most likely I will continue to make most of my own tissue since I like to adjust the color of all my to tissue to something in the original scene, but it will be nice to have the commercial product there as a back-up.

Sandy

 

[Jorge]

Thanks Sandy, I was aware he was doing this. I visit the B&S site regularly. Do you know if he will be offering pigments as well?

I would like to learn how to make my own and, like you, be able to vary the color. The cathedral shot you have on the book is absolutely fabulous, the warm tone you chose fits it like a glove, very, very nice. I would love to learn how to do it like this.

Thanks again for your help.

 

[sanking]

A good place to buy pigments is Douglas & Sturgess in San Francisco. http://artstuf.com/pigments-dyes-colorants.html

I am currently using Cal-Tint and Mixol colorants for my pigment. These pigments come in glycol based aqueous dispersions and mix very well. They are also quite economical to use, especially compared to tube watercolors.

Sandy