8. Mixing Pigments & Glue

The instructions for mixing pigments are fairly easy but this is where a good part of the expertise of Nihonga rests...mixing the right amount of glue to water to pigment ratio for the layer you are painting takes time and experience to master. So be patient with yourself.

• You want the glue strong enough so it sticks to the paper but not too strong or it may crack later or make it hard for additional layers to stick.
  
  
• You want to use a stronger glue mixture on the first layers and progressively less glue on the top layers.
  
  
• You can sometimes correct it if you find the pigment brushing off the paper once dry...indicating too weak a glue mixture...by spraying a light mixture of dhosa over the top and letting dry.
  
  
  

Mixing directions:

1. Take some glue and pigment and mix in bowl with middle finger (i.e. with firmness, you're pushing air bubbles out so glue connects with pigment.
   
   
2. You may want to add a little distilled water to glue but not too much as this point so as not to over dilute the glue.
   
   
3. A fine whitish watery film may rise to the top as you mix, these are impurities, drain this off the top.
   
   
4. For ochre (odo) and many earth pigments, this may be all you have to do before you start to paint.
   
   
5. For mineral pigments...

1. Let mixture sit and dry out...usually overnight. This allows the glue to saturate the pigment.
   
   
2. When its completely dry it will feel solid and hard. Add water to loosen and reconstitute the paint and bring it to the consistency you want for painting. (Mako sometimes does this process of letting the glue dry out and then reconstitute 2-3 times to really get the pigment saturated with glue).
   
   
3. You can now add as much water as you want to the mixture and the pigment will still stick to the paper because the glue has thoroughly saturated the pigment.
   
   
4. You can let the pigment and glue dry out each night if you want and reconstitute it the next day. However if you let the glue and pigment sit too long (a few weeks) it will temper to a hard state and you can't reconstitute.
   
   
5. Cleaning Glue Out of Pigment: If you are going to leave the pigment for more than 4-6 weeks, you may want to clean the glue out of the pigment, returning the pigment to a powder state. Do this by adding water, mixing and letting the glue sit a few minutes so the pigment settles to the bottom. Pour out the top water, leaving the pigment. Do this a couple of times. Then add more water and heat the mixture up. Heat will release the glue from the pigment and it will rise to the top. Then pour out the top and let dry. When dry the pigment should be powdery. If it isn't, add water and heat again and do this until its powdery when dry. This will save your valuable pigments so you won't have to throw them away in hardened glue.

7. Sizing Paper

Paint and ink on unsized paper will absorb down into the paper and not allow you to build up layers. Some special techniques use unsized paper but typically you want to paint on sized paper. You can buy the paper sized already or you can size it yourself. You have more control for preparing the surface exactly as you want it for your own painting needs if you size it yourself.

Use Dhosa to size paper. Dhosa is a mixture of water, glue and aluminum sulfate (also known as myoban or alum)

1. Mix a thin mixture of glue + water, more water than glue, should be a light tint of yellow.
   
   

1. Add a small amount of alum crystals (we used about 1 1/2 tsp for a bowl). Be careful with this as it is acidic and too much will hurt the paper surface.
   
   
2. Let the alum sit and "melt" in the liquid, this might take 10-15 minutes. Mix it well once it has dissolved into the glue mixture.
   
   
3. Designate a wide hake brush your dhosa brush. You don't want to use this brush for other purposes once it has been used to size paper.
   
   
4. In slow even strokes apply the dhosa to the front (typically the smoother side) of your paper. You can stop in the middle of a stroke to re-wet your brush but don't go back over what you have done...start where you left off. If you double size a part of your paper it will take the paint differently in that part.
   
   
5. It doesn't matter what direction your strokes are except each stroke should continue in the same direction.
   
   
6. When the entire paper is sized let it dry. This will probably take several hours, overnight is best.

* make dhosa fresh, it doesn't keep overnight.

* you can use a thinner mixture of this size to stop metal leaf from oxidizing.

* there are many special techniques you can do with sizing, such as putting a layer down on the unsized paper and then apply dhosa, or initially only sizing portions of the paper, then paint and then size again...just be careful about how much alum you use as you don't want a big build-up of it on your paper.

* Dhosa can also be used if you have a layer of pigment not sticking. Spray a light thinner portion of dhosa over the surface and let it dry, this should settle the pigment. (then think about adjusting your glue as pigment falling off the paper is a sign of not enough glue in the pigment mixture).

6. Preparing Glue

Nikawa (glue) is made from hide glue. We used cow-hide sticks from Japan. Different animal hides get different results. Cow hide seems to work the best. (We had some discussion about fish glue which is more readily available in North America. It will work, it isn't as strong as the cow-hide so you may need to use a stronger mixture.)

1. Crack sticks (be careful, they are quite brittle, wrap them in a towel before you break them to be safe).
   
   
2. We used 3 sticks to about 1/2 bowl of water. Glue will last about a week if you refrigerate it. It will go bad though, you will know this by the distinct odor.
   
   

3. Soak overnight (you can speed this up by putting them on a low heat...be careful to not overheat or boil as it breaks the glue apart).
   
   
4. We used metal bowls in class but its best to use some kind of pyrex or even a slow cooker.
   
   
5. When the glue has softened from soaking, heat it gently making sure it doesn't boil. If you have a slow cooker you can use that. I got one from the goodwill store and that has worked fine. The reason they are good is that they don't get that hot. But you can also do it on the stove burner or electric griddle....just watch it carefully and do it on low heat.
   
   
6. The glue will liquify.
   
   
7. Filter the glue before you use it. We used coffee filters in class.
   
   
8. Its actually good to paint with the glue a little warm....that is why something like a griddle is nice because you can periodically return it back to the griddle to warm up. Or if using a slow cooker, leave it on the lowest setting while your working and it will keep it gently warm. If you don't have these then you might want to return it to the stove burner periodically to warm it up....especially when you are in the process of mixing it with pigment.
   
   
9. If you refrigerate it it will become gelatin again, just reheat it. You can reheat as much as you want without hurting the glue...just make sure not to boil.
   
   
   

5. Tearing Paper

Gently crease the edges of the paper to know where you want to tear. You can actually figure this out whatever way works best for you, Mako did it by folding the paper slightly, you could also measure it. The goal is to have some guide for your straight-edge without marking or creasing the paper to any great extent.

Using a straight-edge (in class we used a board because we didn't have anything else but a metal ruler works well, wet the edge you want to tear with your brush.

Using a "bookbinder's bone" score along the straight-edge (do not cut or tear completely through the paper).

Gently but firmly pull the two halves of paper. You will see the fibers feather on the edges.

4. Brushes

Typically use hake brushes for broad washes and thoryu (?), a natural hair brush that comes to a point, for fine lines. Set your brushes in water about 1 hour before using (some artists let them sit overnight) This allows the brush to fully absorb the water, "coming alive" and "broadening out." Don't force the brush when it's not ready or you can damage and lose the hair.

3. Paper

In class we used Kumohada paper, a high quality Japanese paper that is fairly expensive and must be ordered directly from Japan. This is a traditional paper to use with Nihonga and its even texture and consistency accepts the paint well.

However a variety of papers and substrates can be and have been used with Nihonga. Japanese paper is especially good because the Japanese technique for papermaking manipulates the layers of long fibers of the paper pulp in such a way that they interlock, creating a very strong paper. Also the hand-made paper is typically not made with chemicals and is therefore archival. However many western and machine-made papers are also suitable once they have been sized with dhosa.


Here is a video showing how Japanese paper is typically made.


Whatever paper you use, take it out of its packaging once you get to the studio. Paper needs to adjust to the air and environment and should not be tightly rolled or encased in plastic.

2. Pigments

mineral pigments: Japanese pigments are ground into 16 variations from coarse to fine. The higher the number the finer the grind. #11 is more like what is used in the West for oil and watercolor painting. We worked with #9 and #11 in class.

natural mineral pigments: ground minerals mined from various places around the world. They are usually more expensive than synthetic pigments.

synthetic mineral pigments: are created through chemical manufacturing rather than by grinding natural minerals. Their size is much more uniform than natural pigments and usually cost less than natural pigments.

Earth pigments
Although earth pigments don't have the same "refracting" quality of the mineral pigments, they are also used in Nihonga. They are typically fine powder and mix well with the glue. They are especially useful on the first layers of the painting where you want to use the finer ground pigments.

Mica powder can be added to pigment or gofun for additional glisten and effects.

1. Basic Definitions

Nikawa - a hide-glue solution used as a binder for pigments

Kumohada (cloud skin) - commonly-used, hand-made paper from western Japan. Its high quality even texture makes it exceptional for Japanese painting

Dhosa - a mixture of nikawa, water and aluminum sulfate (myoban also known as alum) used for sizing paper

Gofun - powdered calcium carbonate that is made from cured oyster, clam or scallop shells mixed with nikawa is used as a ground, for under-painting, and as a fine white top color.