Making Overglaze Paint for Airbrushing

I spent the morning making a batch of new overglaze paints to use for airbrushing. This is a special batch because I’m going to be painting two bone china bisques in a matte finish. So I have to make separate batches of paints using an added matting agent. I thought I’d photograph and describe the process for the blog.

Overglazes or chinapaints come in powder form. You must make your paints using some sort of oily or liquid medium, depending on your painting style and needs. For the airbrush, I need the paint to be liquid-wet (of course). The chinapaint pigments I use, while very fine, are not fine enough to spray through my airbrush without being grainy. So I have to work at it to get them as fine as I can.

First, I put the pigment powder and an amount of the matting agent powder, into a mortar and pestle. (I’m making black paint, and the matting stuff is white.) I mix them together and then grind them around the bowl:

(NOTE: Normally I should be able to skip the mortar-and-pestle stage, as I am now grinding my paints down using a ball mill. But I don’t have any milled paint at the moment that isn’t already mixed for glossy-finish painting—and ball-milling takes at least a WEEK—so I’m going back to the “old” way for this small batch of matte paints.)

Next I add liquid rubbing alcohol to the ground pigment, getting it nice and wet and mixing all the paint into the alcohol until it is uniform. Then, I pour this wet paint into a laboratory-grade sieve:

This sieve is an ultra-super-fine mesh (.0012″!), designed to weed out all the pieces of powder larger than I’d like to put through the airbrush. It really makes a difference. So I swirl the paint around on the mesh with a spatula until all the fine pigment-bearing liquid has moved through to the pan beneath (and the coarser stuff remains on the top of the screen):

Then, I pour the paint into 1 oz. glass bottles. I like to use glass because I visually gauge the amount of pigment vs. liquid. The pigment settles to the bottom eventually, and once it does that I pour off or add more alcohol. Then I add glycerine, which makes the paint appear the correct/actual color during painting, keeps the paint wet, and suspends the pigment more evenly. Using just alcohol alone as the wetting agent, the alcohol evaporates almost immediately and you’re left with just dry powder on the china. You can’t blend and shade paint that dries like that! Adding glycerine allows the chinapaints to airbrush on just like acrylics or other “normal” paint. That is the essential element that enables me to paint china horses the way I want them to look!

Below: bottles showing mixed paint and pigment that has settled to the bottom:

I just have to shake the bottles to mix it up, pour it in the airbrush paint cup or bottle, and… paint! And they are easy to clean and airtight—airbrush china paints last forever in these bottles. Airbrushing uses surprisingly little paint because the applied coat is so thin. The paint in these 1 oz. bottles is enough for painting the entire base coats on approx. 3-4 horses; many more if I’m only doing detailing and not major body coverage.

Tomorrow, I hope I may actually start painting! !