carbon transfer

Some standard formulas for carbon printing

Some viewers of my carbon printing videos have asked me to write out some of the formulas for the carbon printing materials and processes I demo in my videos. Well, here you go.

These formulas will get you started. However, keep in mind that they can, and should, be changed as you develop aesthetic preferences and want to change your materials to match. For example, different pigments have varying tinting strength and will require different concentrations. A less concentrated gelatin sizing for art paper will provide a less glossy finish. To retain more or less moisture in the tissue, or change the pliability, the sugar can be varied. So, take these formulas as starting points and adjust as you learn.

Note: In the formulas, the percentages of ingredients are intended for calculating the weight of the ingredient as a percentage of the total volume of the solution. For example, a 10% gelatin solution would require 100 grams per liter and 1.2 percent pigment would be 12 grams. Distilled water is recommended, particularly if your water is alkaline. If you are going to spend hours upon hours making prints from your tissue, it's worth using water you know will be good. It also dissolves ingredients better. 

Glop for making tissue

India ink is a good pigment to start with. It is perfectly dispersed, easy to mix, and does not require you to do any extra straining or filtering of the glop after mixing. It produces prints with deep blacks, warm undertones, and a glossy finish. I use Speedball because it is easier for me to buy. It can be bought off the shelf at many art supply stores. Black Cat can be ordered from Dick Blick. Speedball is more concentrated and seems a bit more glossy in finish. The pigment percentages below are simply ones I have used in the past based on their relative concentration.

  • 10% gelatin (250 bloom or greater)
  • 1.2% Speedball india ink or 1.6% Black Cat india ink
  • 4% sugar
  • Water to make
  • 25 ml of isopropyl alcohol mixed 50/50 with water to make 50 ml (an optional ingredient added at the end which can help dissipate bubbles more quickly if you intend to use the glop shortly after mixing)

Art paper sizing

A 7% gelatin solution is easy to coat, sets up quickly to allow you to hang the paper to dry, and gives a reliable printing surface if the paper is thoroughly and consistently coated and the gelatin is hardened. Thinner or less concentrated sizing will provide a more matte finish but will be more prone to developing frilling or blisters on the print when developed.

Hardener for gelatin sized art paper

This is a topic of it's own see my blog post.

Clear

A 3% solution of sodium or potassium metabisulfite will clear the residual dichromate stain from the print. Soak the print for approximately 3 minutes or until the stain clears. Wash in clean water for several minutes afterward. The clearing solution can be reused.

New video - Spotting Carbon Prints

For a long time, I was terrible at spotting prints. To make matters worse, carbon prints have some properties that make them particularly difficult to fix. After nearly giving up, I developed some techniques that have worked well for me and have helped me save prints I would have sadly sent to the trash bin. 

In this video on my YouTube channel, I cover some of the challenges, techniques, and spot a recent print.


Carbon printing part three - pouring glop

After watching me blather on in parts one and two, here we get to business and pour some glop. There are a variety of ways to make tissue and this video shows the method and jig I happen to be using right now.

I have one clarification to make. In the video I talk about measuring the volume of glop to get an approximate 1mm wet height. I still think in square inches. So, the correct factor to get the volume in milliliters is .645 not 6.45, if you are converting from square inches. 

Carbon printing part one - overview

There are already a few YouTube videos that demonstrate some of the steps in carbon printing, but I've wanted to make a few of my own. Everyone's process and methods are different. So besides helping explain how I print to folks who have never seen carbon printing before or getting some interested in learning, these clips may be of interest to experienced printers as well. I am always interested in how others have mastered carbon's many quirks and idiosyncrasies.

I will continue this series through to a finished print. To start the series I covered making glop and coating tissue. Each one I was able to do in one take as I made some new printing tissue this weekend. I had intended these to be a little shorter, but, as usual, I get excited about explaining this stuff.  As always any feedback is appreciated, and I can teach workshops if you are interested. Watch from this blog post or visit the YouTube playlist where I will post all the videos from this series. 

A couple of clarifications in this one:

1. I refer to Arche Platine as watercolor paper. It's printmaking paper made especially for platinum printing, but it's consistent sizing makes it very good for carbon. Expensive though. See my post on paper for more opinions and experiences regarding paper.

2. Yupo, which I mention a couple of times, is the brand name of a polypropylene paper substitute that is perfect as a temporary support. You can buy it at almost any art store in pads or in sheets and rolls.  

My new carbon tissue jig

Lately I've been planning to make some larger carbon printing tissue for prints in the 16x20 range. That means that I had outgrown the surface area of my old jig for pouring out glop. I also wanted to start making thicker tissue again, and pour out glop at a wet height of about 1mm.

My favorite surface for this is glass. It's perfectly flat, cleans up well, is portable, and absorbs the heat of freshly poured glop to allow it to set up quickly. This new glass jig allows me to make tissues up to 24x24 in size.

Instead of going for a magnetic surface that allows me to use magnetic strips to dam the liquid glop, I am using 1/4 inch strips of glass backed with electrical tape. The glass strips are easily arranged to form a dam for sheets of different sizes. The tackiness of the electrical tape and the weight of the strips is enough to keep the strips from moving once they are set down. I had considered rubber strips, but the electrical tape works just fine.

The base surface is a 1/2 inch thick table top I bought in Craigslist for 60.00. The base is heavy but easily portable and can be easily leveled with shims if necessary. This allows me to set up the jig in my kitchen where I like making materials the most. I just set it on my work table and put it away when I am done.

The only limitation of using the glass strips to dam the glop is that they will always be much thicker than the wet height of the tissue. This means that you cannot level the tissue with a metal rod. You have to set your thickness by pouring out the exact volume. However, so far this has worked out well. The glop has to be very hot, but I can effectively spread it out with a comb to get a smooth and level coat.

 

 

 A perfect 11x14 sheet ready to dry. If you like set your tissue thickness by pouring by volume, this jig works like a charm and cleans up nicely.

A perfect 11x14 sheet ready to dry. If you like set your tissue thickness by pouring by volume, this jig works like a charm and cleans up nicely.

Papers for carbon printing

Fine art paper is my favorite surface for carbon printing. It has a subtle quality that other papers, like fixed out photo paper, simply cannot match. However,  printing on hand coated papers introduces a level effort and difficulty that can be discouraging. It's maddening to put the effort into preparing and sizing paper only to find out that the paper won't print well. 

Like my post on methods for hardening gelatin sized paper, this post is a running record of papers I'ver used for carbon printing and how well they have worked for me. I'll also include some reports from others. I'm omitting fixed out photo paper from this list since that's an entirely different animal. If you have an experience, with a particular paper you would like to share, drop me a line.

Arches Auqarelle

This paper was one of my favorite for Kallitypes. It has a nice smooth finish and great wet strength, but, despite being tub sized with gelatin, the sizing seems consistently inconsistent. Spots can been seen when the paper is wet and, although these spots disappear when the paper dries, these areas can often shot up lighter in the final print and ruin it. I think this problem is mitigated if you heavily size the paper with 7% gelatin or greater. However, with thinner sizing you run the risk of an inconsistent printing surface.

Arches Platine

Like Fabriano Artistico I've had great results with this Platine. It's originally designed for platinum printing, and is expensive. However, I've tried it for it's quality and the fact that it is supposed to have internal sizing that will help it dry flat even after multiple washes. This paper is smooth, strong, has consistent sizing, and seems to dry relatively flat even with heavy sizing. While not as heavy as the Fabriano it has good a good weight and feel.

Fabriano Artistico

I've had great results with this paper. I am hard pressed to tell you the specific type, but what i have used is the 100% cotton variety in natural and bright white. I believe this is different than the F5 variety which is only 50% cotton. This paper is smooth, strong, has consistent sizing, and seems to dry relatively flat even with heavy sizing.

Magnani Pescia

I had high hopes for this paper. It's 100% cotton and smooth hot pressed. It's also has a heavy weight and a feel of quality at an economical price. 

Unfortunately, after the rigors of sizing and carbon development, it delaminates and peels into layers - particularly at the corners. it also had a nasty tendency to get creases easily when bent. This problem seemed to be a symptom of the first. The paper seems to be pressed in layers instead of moulded. When the layers start to come apart, the paper can buckle and crease. It's probably great for some uses, but I won't be sing it for carbon again.

Stonehenge

I just recently tried Stonehenge again and realized why I stopped using it in the first place. The wet strength is terrible. If you can get it sized and hardened without tearing it, the gelatin will give it more strength, but it's risky and just not worth the bargain price.

Adox Baryita

You can print on it right out of the package. No sizing required and no need to fix out like silver gelatin. However, I wasn't wild about the finish. It yielded what I thought was a rather boring finish. Kind of dull and flat.

 For me, Arches Aquarelle had been a trustworthy paper with great wet strength, but here, in a wet print, you can see evidence of inconsistent sizing that can cause light spots in the final print.

For me, Arches Aquarelle had been a trustworthy paper with great wet strength, but here, in a wet print, you can see evidence of inconsistent sizing that can cause light spots in the final print.

No it's not a bong

It’s a rod heater. For making carbon materials, this has turned out to be one of my most useful tools. When coating paper or making tissue, it’s a pain to have to constantly refresh a tube of hot water to keep the coating rod hot. Often the rod is too cool or the temperature is inconsistent. The hottest water rises leaving the bottom of the rod cooler. All in all it makes for a tedious session

Rod Heater.jpg

It was simple enough to build. The key component is the heating element. It is a simple electric beverage heater you can get at Ace Hardware. The heating element is stuck through a hole in the black rubber end cap that is attached to the end of the wye fitting. Epoxy glue keeps the hole in the end cap water tight. The wye keeps the element out of the way  of the metal rod. The switch obviously turns it on and off.So, for about 20.00 and a couple of trips to the hardware store I was able to make a fully electric rod heater. The only things it lacks is thermostatic control. Maybe I’ll add that feature for v2.

The rest of the pieces are PVC pipe and fittings to suit the dimensions of your coating rod. I’ve found that 2″ pipe is more than adequate, but I like the transition to the larger 4″ at the top as it makes the heater easier to fill and the rod easier to grab. The only other price of interest is the base. That is a PVC toilet flange. The wide base allows it to stand upright wherever I want to use it.

To give the heating element a head start, I fill the tube with hot water from the tap and turn it on. However, it will heat a tube of cold water in about fifteen minutes. I keep a check on the temperature of the water and simply turn it off at the switch when I want it to cool a bit. It can make the rod too hot. When I am coating a sheet of Yupo for tissue, a rod that is too hot can cause the Yupo to buckle a little. One thing to remember is to never turn the heater on and pour water on it. The thermal shock will cause the element to break and you’ll be headed back to the hardware store for another heater.

Hardening gelatin sized paper

This post is a running record on how I have hardened gelatin for sized art paper. I generally coat my papers with a 10% gelatin solution using an RD-95 coating rod for a .25mm wet hight thickness. To my surprise, I have found coating papers and finding good hardener to be as challenging as making my own carbon tissue. I have currently settled on using formalin as it works wonderfully and is perfectly safe when used outdoors in low concentration.

Formalin

Know to work well in all ways, but toxic. Formalin hardens perfectly and doesn't leave a cast in the paper or gelatin. For these reasons, I avoided using formalin for a long time, but finally decided to give it a try for my last batch of papers. Following recommendations from others I used a 2% solution of formalin 37. That's a 2% working dilution of a 37% stock solution. I hardened the papers in a tray outdoors and pre-soaked the papers before putting them in the formalin. 

The combination of the dilute solution and soaking outdoors made left almost no odor. So, I felt confident that I wasn't putting myself at risk. I soaked each paper for about a minute and put them on a clothesline to dry. The formalin can be reused. I am not sure how to judge when it would be expended. So, there is little environmental impact. 

The results were perfect. The gelatin was perfectly hardened and there was no change in the color of the paper. The process itself was also very easy. Combined with soaking and drying outdoors for safety, formalin will be my go to solution for hardening from now on.

Glyoxal

It's far less toxic than formalin and hardens well, but does produce some yellow stain in the paper. Much of the stain washes out in development and clearing but not all. My method to date has been to put about four drops in 75ml of gelatin, and this works well. I would like to try brushing it on after coating and drying. This would minimize my exposure to it and keep my gear from getting as gummy while coating.

Alum

The key is knowing the difference between potassium alum and chrome alum. Potassium alum is relatively harmless. It's apparently the same stuff they put in the little pencils used to stop bleeding from shaving knicks.

However, it does not harden well and is difficult to wash out of paper. So, it can be good for hardening paper that will be used as a final support in a double transfer carbon print. However, when I tried to use it for a single transfer, it hardened the gelatin in the tissue during the mating to the support and ruined my prints. 

Chrome alum apparently hardens well but is far more toxic. I have been told it can also leave a nasty blue cast to the paper.

Gluteralhyde

Never used it, but given it's toxicity, I would probably just use formalin.