Archive for the ‘Discoveries’ Category

h1

Shiva Casein Paint Test Update

July 24, 2017

To follow up on my previous post, I had found that one of my Richeson/Shiva paints, Cadmium Green, transferred to a dry paper towel with just some light rubbing after the paint had dried. Now I wanted to see if other tubes I owned had this same problem. They do.

This picture shows a sheet of paper on which I painted 1 inch swatches of all the different tubes of Shiva paints I have. The paper towel at the bottom shows pigment from each swatch that transferred over. I did not dilute the paint at all with water, and did not apply the paint too thickly. All of the paints smeared easily when rubbed, some more than others, with the sole exception of the Raw Sienna. The ivory black in particular smeared very badly, and even after a day of drying felt to have a weak paint film.

Since all of the paints are old, in some cases decades old, I asked around to other people who used these paints if they could test any tubes they might have that are newer, and see if they had the same problem. I heard back from a couple people. One person had some Richeson caseins that were only months old, and found they had the exact same pigment transfer problem. The other artist rubbed the surface of paintings he had made that were at least 3 months old, and said no paint at all rubbed off. What this tells me is it might be possible that if the paint is allowed to cure for awhile longer, the pigment will adhere better and not rub off. This strikes me as a strong possibility. So, I think I’ll do a new test on paint swatches that sat undisturbed for a month or more, and then see if any pigment rubs off.

h1

Comparing My Casein Paint to Shiva Brand

July 22, 2017

I wanted to follow up on my previous post where I made my own casein white paint, and see how well it compares to tubes of the Shiva paint I had, and discovered something interesting. I used the paint swatch I made testing my paint on a sheet of Strathmore textured “Art Paper” 65lb.

I painted a small swatch of the Shiva titanium white, undiluted, next to the swatch of mine I had made. It may be hard to tell in this photo, but I noticed their white has a slight off-white yellowish tint to it that mine does not. I let this dry for a day, and came back and gave both a buffing with some colored fabric, and saw no transfer of pigment from either swatch. Next I placed a small piece of cellophane tape over each one, rubbed it, and removed the tape. Both transferred some paint, but more paint came off the Shiva swatch, lifting almost all the paint from the paper. The casein binder I used to make my paint was over a year old, so later I’ll see if a fresher batch performs better.

Since that tube of Shiva white is many years old, I thought I’d test a newer tube of Cadmium Green that I had to see if it performed any better. Rather surprisingly the pigment adhesion was worse. I let that paint swatch dry for about 3 hours, and rubbed the surface with a paper towel. You can see quite a bit of pigment rubbed off. The tape test pulled off quite a bit of pigment also, and the way the pigment transferred was not in sections of paint, but powdery like what I saw on the paper towel. This tells me that the adhesion on this tube of Shiva paint is poor. Granted, it’s about 5 years old or so, but it shouldn’t come off this easily. I have commercial tubes of gouache that adhere better than this. I hope the newer Richeson brand of Shiva adheres better. Now I want to test the rest of the Shiva paints I have. This is not terrible, but surprising. This paint adhesion is not much better than soft pastel.

h1

Plaster Coated Paper for Gouache Paint

May 4, 2017

As I get ready to prepare the surface for my new painting, I wanted to test out a ground to use especially for the grass area I’ll be painting. I’ll be using a large sheet of illustration board, and coating it with a thin ground made with spackling compound.

Spackling is a paste made out of (typically) calcium carbonate, silica, and glycol. You can find it at hardware stores, and it’s used for filling small holes and cracks in walls prior to painting. It can be thinned with water. I’ve added a small amount of acrylic medium to improve the adhesion and make it more flexible. In the picture above, I’ve drawn an area in pencil to show the rough texture it makes. It feels like a fine grit sandpaper. I applied just one coat. It creates a nice paint ground, but can lift if you use a very wet wash. Adding acrylic medium helps prevent that.

The main reason I’m using this particular ground is to allow me to lightly scrape away paint layers. You can see the marks I’ve made on the small test area of gouache paint in the picture. It will help me create a more convincing grass texture. The tools I used here are a bamboo pen and a solder scraping brush. The bamboo doesn’t dig too deeply into the plaster, and the steel brush gives a fuzzy, random scratch. I’m using various commercial gouache paint, as well as a couple of my own. This should work well for me.

UPDATE:
I’m adding a closeup of the painted area to show the scratch marks better.

h1

Sinopia Casein Gesso Update: Jar Problem

May 2, 2017

I’m interrupting my series of posts on the new painting to point out a problem I discovered today with a jar of Casein Gesso from Sinopia. This follows up on two posts I made in the past: one is a review of this product, and another was how I store paint containers like this upside down.

I bought this jar of gesso a little over a year ago, and keep it inside a drawer in my studio. I haven’t used it in awhile, but today I decided to open the drawer to try it out again, only to find the contents had leaked out. The lid was screwed on tight, but that wasn’t enough to stop air from getting in, and some of the contents leaking onto the drawer. Fortunately that was plastic, so it was easy to clean (that’s what that clean piece of gel is in the picture,) but I had to use a plumber’s wrench to get the lid off, and found that about 1/3 of the paint had dried out. That rounded disk inside the lid is about 1/2 inch layer of dried paint, and more dried on the sides of the jar. It had been stored upside-down.

As I mentioned in the article link above, I store containers like this upside down just for this reason. Screw-on lids of this type make very poor containers for paint, since air gets in easily. Even if this was stored upright, air gets in, and would have dried out the paint even worse. Some jars you can buy come with cushions inside the lid, sponges or thick paper, that help seal the jar. Another solution I’ve used in the past is to wrap wide tape around the outside. That has to be replaced frequently, but it’s better than throwing away paint.

Metal cans for paint make a better seal than a screw-on lid, unfortunately, a quart size can is the smallest available. Tubes are also better since the opening is smaller, so less air gets in. The best option is to use it up quickly. Prime several sheets of paper stock or canvas that you have on hand, and don’t store the left over paint for very long.

h1

Watercolor Paper Stretcher – Version 3

November 1, 2016

My previous version of a paper stretcher worked well enough, but it was a bit awkward and bulky in the design, so I came up with another modification.

paper-stretcherb1

I replaced those 4 strips of wood clamped to the outside edge with several small strips of wood glued to the back of the frame and flush with the outside edge. Now I don’t have separate strips of wood to carry around or lose.

paper-stretcherb2

In place of the screw clamps, I’m now using 2 inch binder clips attached to these strips of wood. I can fold the wet paper around the edge, and use the clips to hold it place. Now I don’t have to tape the paper to the back when it dries in order to remove the clamps. I can leave the clips on while I’m painting.

paper-stretcherb3

The metal handles on the clips are also removable, which makes the frame sit better on an easel or flat on a table.

paper-stretcherb4

This frame is 16 x 20.” I may build a larger one, and have the four 1/8 strips go along the whole length of the outer edge so I can place the clips wherever I want. I didn’t have enough scrap wood for that this time, but this will work just as well.

h1

Homemade Casein Fixative

October 27, 2016

I’ve been meaning to make fixative out of casein for some time now, but until recently I haven’t done much art in a medium that need it. Today, I was in a conversation with an online friend about types of fixatives, and this subject came up, so I thought it was a good time to make some and test it out. Conclusion: it works very well.

caseinfixative00

If you’re possibly new to the term “fixative” and its use, it’s a coating that is added on top of dry media (charcoal, pastels, graphite, etc.) to keep it from smearing. Most commercial fixatives come in aerosol cans that use an acrylic resin. There’s a commercial brand of casein fixative on the market called SpectraFix. I’ve tried it, and it works okay; although, I’m not too fond of their pump sprayer.

I first heard of using casein as a fixative in a book about Paul Gauguin and his pastels where he learned this technique from Camille Pissarro. I later found a recipe for it in the Reed Kay book “The Painter’s Guide to Studio Methods and Materials.”
1 part by volume casein solution
2 parts by volume grain alcohol
5 parts by volume (distilled) water

The casein solution I used is the same as I always make for a base medium to start from. I describe it here in my most recent batch I made back in April. It has a couple drops of Thymol preservative in an 8 ounce mixture. It’s very easy to make. This batch came from raw milk, but it can also be made from dry casein powder, which I’ve talked about before. The grain alcohol I’m using is Everclear, which is 190 proof. A good clear Vodka could also work.

Mixing it was simple enough, so to apply it I used the Preval sprayer I wrote about a few years ago. I’ve used it occasionally for spraying primers and it works great. I found that the spray comes out with a little more force and volume than most aerosol cans I’ve used. As such, I knew to step back about 2 feet with the art surface upright, and move across the art in a quick sweeping motion; starting the spray off the art and finishing off the art.

caseinfixative01

caseinfixative02

The plastic sheet above has the fixative on it, and the sheet below it has none, so you can see how it turns the plastic very dull. When sprayed on paper, even black paper, I don’t see anything. Held up to the light, I can’t see any reflections. Each coat dries very quickly, under 10 minutes. When soft pastels were sprayed with two coats, I didn’t get any smearing.

caseinfixative03

At first, I got worried when I sprayed the grey pastels above. The whole image almost disappeared, but it came back as the fixative dried. It lost a little of it’s brightness, but otherwise worked fine. On the white paper sample, the color pastels didn’t seem to change value at all. It also works well on soft graphite pencils and charcoal.

I would have no concerns using this fixative on my finished work. I could also layer it; although, I would be reluctant to build it up too much – 3 to 4 coats max. The water content could cause paper to buckle, especially thin paper, unless it was stretched or taped down before the drawing was started.

h1

Preview: Drawing on Liquitex Clear Gesso

October 19, 2016

In my ongoing exploration of drawing surfaces, I recently picked up a bottle of Liquitex Clear Gesso. An online friend was looking for a way to prime wood for oil paint but still let the grain of the wood show through. I suggested this product, and noticed that it was also recommended for drawing with pastels or other dry media.

liqutex-cleargesso1

Here I have painted a small square of the gesso on a sheet of black poster paper, and drew on it with a selection of different pencils; pastel, watercolor, graphite and charcoal. The media has a gritty sand paper texture like Ampersand’s Aquabord, or other similar acrylic primed surfaces that are made to have more tooth than regular acrylic dispersion (“gesso”) primers. It feels a little rougher than the Acrylic Ground for Pastels made by Golden. I suspect there’s acrylic resin mixed in to make it clear, since the Pastel Ground has silica and looks grayer when it’s wet. You can add water mixable paints or inks to color this gesso if you wish, and it can be thinned with water.

liqutex-cleargesso2

The particles catch the light and will give the surface a slight sheen at an angle. It’s thinner than regular acrylic gesso, more like acrylic medium. To avoid brush marks you might consider thinning it and applying multiple coats to make the strokes less noticeable, or use a sprayer. An eraser won’t work well removing any marks, but you can dab the surface and lighten them with an eraser. I noticed that if this gets slightly scratched it will leave scratch marks behind.

liqutex-cleargesso3

You can also paint on this with acrylics, gouache, casein, or oils. The tooth will give the paint something to adhere to on any hard slick surface, but it’s recommended that the surface first be sanded before applying the gesso, which might be noticeable through the clear gesso. My main complaint with these rough surfaces for painting is that they really chew up my brushes.