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  1. #1
    paul_c5x4's Avatar
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    Mixing gloop for carbon transfer

    Looking at the (few) recipes for mixing the gloop for carbon transfer printing, they all appear to be pretty similar - 80-100g gelatin per litre plus a spoon full or two of sugar. However, the recipes seem to be somewhat vague on the quantity of pigment to add, and suggest either india ink or a tube of water colour.

    My local artist supplies stock a range of pigments in pure powder form and I now have a bag of ivory black to use... A question for the experts: Typically, how much of this raw pigment should I be using per litre as a starting point ?

  2. #2
    Vaughn's Avatar
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    Using powdered pigments will be a challenge, but certainly not an insurmountable one. The trick will be to get a even dispersment though-out the gelatin without clumping of the pigment. I use lampblack watercolors -- about 5 grams or so for a liter of glop. It is easy to mix in and gives me good consistancy. How much of that 5 grams is the actual carbon, I do not know -- most of the weight is probably the water and gum arabic.

    I'll remain vague on the actual amount of pigment -- that varies so much from the pigment type and the company making it, and by what one wants the print to look like (pigment concentration affects contrast, raised relief, tissue speed, et al).

    Good luck!
    At least with LF landscape, a bad day of photography can still be a good day of exercise.

  3. #3
    Hexavalent's Avatar
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    If you're just starting out making carbon tissue, do yourself a favour and buy some India ink.

    Dry pigments can be a real pain: my experience is that the dry pigment needs to be blended with a carrier (typically gum arabic) and then added to the gelatin mix.
    Getting a clump-free pigment mix takes a fair amount of blending: I used a palette knife on a small piece of glass -- pinch of pigment, drop or two of gum, mix blend, mix, little more pigment, little more gum, drop of water..mix, blend, mix and so on, and so on. A drop of photo-flo and/or alcohol may help with the dispersion. It is messy.

    As powdered pigment tends to be light fluffy stuff, try making a mix of pigment/carrier (say 1 tsp each or whatever makes a nice paste), and then determine how much of that is needed to produce 'glop' with the density you desire.

    I use 'Royal' India ink for most work, tweaking the colour with watercolour paint if needed - it's repeatable and much simpler than using dry pigments.
    Last edited by Hexavalent; 09-14-2010 at 01:28 PM. Click to view previous post history.
    - Ian

  4. #4
    Vaughn's Avatar
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    Black Cat Ink (from Dick Blick) is another favored ink for carbons -- have not used it. Might someday.

    Vaughn

    PS...I use more than a spoonful or two of sugar -- about 80 grams per liter. This is on the high side of normal, but it works for me in my climate and process.
    At least with LF landscape, a bad day of photography can still be a good day of exercise.

  5. #5

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    Quote Originally Posted by paul_c5x4 View Post
    Looking at the (few) recipes for mixing the gloop for carbon transfer printing, they all appear to be pretty similar - 80-100g gelatin per litre plus a spoon full or two of sugar. However, the recipes seem to be somewhat vague on the quantity of pigment to add, and suggest either india ink or a tube of water colour.

    My local artist supplies stock a range of pigments in pure powder form and I now have a bag of ivory black to use... A question for the experts: Typically, how much of this raw pigment should I be using per litre as a starting point ?
    Recipes are vague about the amount of pigment needed because the strength of colorants varies a great deal depending on type and manufacturer. I would avoid powder pigments unless there is some particular color you are after and it is not available anywhere else. You can make dry pigments work but it is a lot of trouble and does not make a carbon print any better than easier to use pigments like tube watercolors, Sumi ink, India Ink or Black Cat or Speedball Ink that you can buy from Dick Blick.

    You will find that the actual amount of gelatin and siugar also vary a lot because there are many different kinds of gelatins and people in different areas of the country prefer to use more or less sugar. I use one gelatin that needs a 14% solution to have the same working characteristics as another that needs only 10%. And I typically use only about 30 grams fo sugar per liter, which is on the low side.

    Sandy King

  6. #6
    holmburgers's Avatar
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    Slightly off topic, but what is commonly used in tri-color carbon for the CMY? Again, watercolors?
    If you are the big tree, we are the small axe

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    Quote Originally Posted by holmburgers View Post
    Slightly off topic, but what is commonly used in tri-color carbon for the CMY? Again, watercolors?

    There are only a handful of people making tri-color carbon prints so I would not say that any specifc pigment is "commonly used." Tube watercolors work fine but are quite expensive compared to other pigments that disperse in water. If I were to do this I would probably try the Createx brand of colorants, or perhaps Cal Tint II or Mixol colorants. As I recall three-color sets are available with all three of these brands. The pigment inks that are used for inkjet printing would also work well and would make for very smooth prints, but would also be pretty expensive.

    Sandy King

  8. #8
    holmburgers's Avatar
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    Thanks Sandy, 'tis a shame that so few are doing tri-color.

    Mind if I PM you with some more specific questions? I don't want to hijack this thread just for my sake.
    If you are the big tree, we are the small axe

  9. #9
    lxdude's Avatar
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    Is gloop a technical term?
    I do use a digital device in my photographic pursuits when necessary.
    When someone rags on me for using film, I use a middle digit, upraised.

  10. #10
    Vaughn's Avatar
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    Quote Originally Posted by lxdude View Post
    Is gloop a technical term?
    Perhaps in Great Britain -- on this side of the Atlantic the technical term is "Glop"
    At least with LF landscape, a bad day of photography can still be a good day of exercise.

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