Archive for the ‘Techniques’ Category

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Making Red Oxide Casein Paint for New Painting

January 7, 2018

As I’m starting to work on the background of the new painting, I noticed I was too low on the red oxide paint that I wanted to use, so I needed to mix up some more.

I also wanted to test out the package of Bob’s Red Mill milk powder I bought recently to see how well it works for making a casein binder. 1 quart of rehydrated milk gave me a little less than 6 ounces of casein when I added 1/2 cup of vinegar. That’s the separated milk liquid on the right. I’m used to seeing the milk coagulate into a large ball after I add the vinegar, which I then tear it into small pieces so it will dissolve better. This milk forms small clumps of casein instead, as seen here, so that saves me an extra step.

I added about 2 teaspoons of Borax diluted in 1/2 cup distilled water to this casein, and let that sit for about 24 hours to form a thick smooth gel. This will be my paint binder.

The red oxide pigment was purchased from Camden Grey. A one pound bag cost me only $3. It makes a lovely dark red burgundy color that mixes very easily with my binder. I’m waiting on an order of empty paint tubes to arrive, so I’m using a one ounce jar in the meantime.

Here’s a scan of the paint on a piece of watercolor paper. I painted it over some black Sharpie marks to show how opaque it is. It also thins down nicely. Now I’m ready to get back to work.

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Polyester Fabric Mounted to Hardboard

November 30, 2017

I’m preparing to start another painting, and wanted to use some polyester fabric I had. First I needed to mount it to a hardboard panel.

This shows a 16 x 20 inch panel with the fabric glued to the front. To get to this point I had to prepare the panel first. It was a scratch panel I had in the studio that had a few thin spots of white paint I needed to sand down. I used some acrylic “gouache” paint I had and mixed it with some GAC-100 medium to both prime and size the panel. I thinned this a bit with water to make it more brushable, and covered the panel in two coats.

I roughly cut a sheet of the fabric about 2 inches larger than the panel. It had a few creases in it, so I used an iron set to low heat to smooth them out. Once the paint had dried to the touch, I covered that with some Liquitex Extender Gel to use as an adhesive for the fabric. This also had to be thinned a little. I dropped the fabric on the wet panel, and used a brayer to roll the fabric smooth. I left this sitting under some weight for a few hours to keep the panel straight as it dried. Later I’ll glue the edges to the back, and trim them to make them look less ragged. Now all I have to do is figure out what I’m going to paint…

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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.

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Making a Panel with Acrylic Ground for Pastels

August 26, 2016

Now that I’m between projects, I wanted to use this time to finally test out this Acrylic Ground for Pastels made by Golden that I bought a few months ago. My true plan is to see how well it works with gouache paint.

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As a test panel, I used a scrap piece of hardboard, 8.5 x 11″. It had a little dried white acrylic paint rubbed into the surface, but I figured that wouldn’t be a problem. First I sized the board with a couple coats of GAC 100 medium to keep anything in the wood from leaching up to the surface. You’ll notice in the photo above that the ground is somewhat gray and translucent. It doesn’t have any pigment in it, like an acrylic “gesso” ground. That gray color is from finely ground silica that gives the surface some tooth for pastels.

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The label instruction says to not thin it with water more than 40%. This photo shows what it looks like with 3 coats. The first two coats where not very thin, maybe 10-20%. The last coat was thinner. I noticed that the brush left behind a few small gouges in the surface caused by some larger particles of silica, so I dug that out and filled the tiny holes with undiluted ground using a palette knife. I wouldn’t want to do that with a true gesso surface, but with this acrylic medium it isn’t a problem to patch it that way. I suspect that if I had waited for each coat to dry longer and harden, it wouldn’t have had those gouges.

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I wanted to even out the color a bit, so I mixed up a thin wash of acrylic “gouache.” This will be porous enough for regular gouache paint that won’t lift.

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The final result I left a bit patchy, but that’s okay. Now comes the fun part of figuring out what to paint on it.

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Framing Tip: Cutting Acrylic on a Tablesaw

May 8, 2016

One of the unique tricks to building a frame for a drawing is cutting the acrylic glazing sheet. The tool most often recommended for this procedure is a special hooked knife designed just for this, but I can’t comfortably tell you the number of times that has gone wrong for me. You have to score the acrylic in several passes, it’s hard to keep a straight line on the smooth sheet, and it almost never snaps cleanly. Fortunately, I’ve discovered it’s much easier to do this with a tablesaw. Acrylic will not cut like wood, however. If you try to cut all the way through, the blade will just destroy the sheet. Here’s how I do it.

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First, I’ve cut some cardboard to the size of the frame interior to use as a guide, taping it to the edges of the acrylic. I’ve also taped some newspaper to the front to protect the acrylic from getting scratched while pushing it on the table.

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Set the blade depth to cut no more than halfway through the acrylic. Just like using a knife, you only want to score the sheet, not cut all the way through in one pass.

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The acrylic snaps off easily. There will be a few rough burs along the edge, but that will scrape off easily with a utility knife, and get smooth with some sand paper. You can also flip the sheet over, and carefully saw off any excess on that side.

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Here the sheet is placed in the back of the frame. By the way, that’s my new frame I bought the other day all glued together. I just need to insert the artwork and fix the backing.

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Enlarge a Drawing Using a Computer Monitor

September 1, 2015

I wanted to enlarge this sketch to a larger size, and I can use my computer monitor as a sort of light table to help do that. The drawing is on a sheet of 8.5 x 11 inch paper, and the size I’m enlarging to is about 18 x 24 inches. Here’s how I did that.

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I scanned the drawing at 200 dpi. The viewing software I’m using is IrfanView, a freeware program for Windows. You can use any other viewing software as long as it allows you to zoom out to full screen without any distortion.

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Next I zoomed in to a size that displayed on the screen the exact size I wanted the artwork to be. In this case that was 4 times (with IrfanView press the + key 4 times.) I then scrolled the screen to the left and up all the way so that the top left corner of the screen was the top corner of the scan.
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I held a thin sheet of copy paper, 8.5 x 11″, on the left corner, and copied a reference mark from the scan to the paper. If you don’t have a mark on your drawing that fits into the area of the sheet of paper, add one on the drawing (such as an “X”) and scan it again.
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Now I scroll directly to the right top corner, hold up another sheet of copy paper, and make a mark using the same reference point of the drawing.
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I then scroll down as far as the image will go, hold another sheet of paper to the screen, and make another mark at the same reference point. The last step is to piece all three pieces of paper together.
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I laid the three sheets of paper on the floor, and overlapped them so that the reference points lined up. I then squared them up with two t-squares, and determined that the outer edge measurements came to 17 x 22.”
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I will now use a 17 x 22″ sheet of paper (newsprint paper works well, or I could tape 4 pieces of copy paper together) to trace the image from my computer monitor, and then transfer that to whatever surface my artwork will use.

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Paint Storage Tip: Gravity Is Your Friend

July 22, 2015

Some fatherly advice I received years ago from dear old Dad was to store my containers of liquid, in particular cans of paint and such, upside down. The demon of air will dry out paint, or cause it to get a dry skin layer inside the can as air that penetrates through the lid. However, when the wet liquid presses against the inside of the lid there’s less air to dry it out, and the paint will last longer.

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In this photo above you can see a few small plastic jars of some recently made gouache paint turned upside down on their lids. This is how I store them. Sometimes I put labels on the bottom. Behind them is a jar of Golden Acrylic Gesso, a bottle of acrylic medium, and some paint tubes. The bottle of medium is a little unwieldy on its cap, so I have to place it in a drawer in such a way that it won’t tip over, usually against other similar bottles stored in the same way. The paint tubes can be a problem since most manufacturers use very small caps that won’t let you balance the tube upright. Liquitex tubes are nice and large for that, but not most other brands. Alternatively, you should squeeze the tubes from the end, forcing the paint to the top and get the same benefit.

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This is also a good way to store any cans of left over house paint you might have in the garage. Be careful of potential leaks, however, and put a plastic sheet underneath, just in case.

The motivation for this post was my reading that Golden is going to start labeling their cans upside down to encourage people to get use to this way of storing their supplies. Good for them.