Archive for the ‘Techniques’ Category

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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.

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Giving a Finished Oil Painting an Even Shine

July 17, 2014

Some time ago I wrote a posting about how paintings can display an uneven shine on their surface that can be annoying when seen from the side. I can resolve this by properly applying a final varnish coat, but it takes time before the painting will be ready for that. There is another option involving the use of an “oil painting medium.” The technique is referred to as “oiling out.”

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This medium is sold by a number of different brands. The one I have is from Winsor and Newton. It’s made with a combination of linseed oil and resin.

When your painting has become dry to the touch in all areas, look at it from the side and you will likely see spots that have different reflective qualities. Some patches will have a “sunken in” or matte look to them in comparison to the rest of the painting. This is caused by the type of pigment and/or medium choices you have used. Applying this painting medium to the surface will even out those dull patches and give the whole painting an even shine.

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In this example I’m using my recently finished oil painting. On the bottom of this picture you can see how there are uneven areas of dull and shiny patches. At the top edge I’ve started to apply a very thin coat of this painting medium that causes the surface to shine evenly. I’m using a clean cotton muslin rag to dab the medium onto the surface and work it into the paint, and then I go back over this with another clean rag to even it out. Keep this coat as thin as possible. After a few days it should be completely dry.

Note that this acts more as a finish than a varnish. You’ll still want to give your painting a final varnish coat after a few months have passed.

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Fixative Spray on Charcoal Drawings

May 4, 2014

krylon-fixatif

I wanted to take a moment during the process of this charcoal drawing I’m working on to share my experience with using fixative sprays. The purpose of a fixative (a.k.a. fixatif) is to adhere the loose dry mediums like charcoal, pastel, or graphite to the surface and prevent them from smearing. This is accomplished by acrylic resin in the spray.

Most fixatives come in spray cans. There are “workable” or “final” options. Final is essentially a varnish. “Workable” is what I prefer to always use. This type allows me to continue to add more drawing to the surface if I choose; whereas, a final should only be used when the drawing is finished. I get best results by holding the can no closer than a foot from the surface, preferably outside in a slight breeze that will diffuse the spray more. 1 coat is adequate for the lighter shaded areas, but the darker areas will need more. You can still lighten (but not completely erase) areas that have only 1 coat, and dark areas would still smear, but 2 or 3 coats cannot be erased or smeared. Let the spray dry about 10 minutes between coats, and an hour before drawing over the workable sprayed area.

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I want to be certain that any loose charcoal powder is off the drawing before I spray it. First, I’ll tap the back of the drawing facedown over some newspaper to get off as much as I can. If you hold the can too close to the drawing, the air will blow around any loose powder, which can be a problem in carefully rendered areas. Spray the fixative in a direction where any blown powder will cause the least noticeable problem, ideally off the edge of the paper, or across dark areas. You can also mask areas with sheets or pieces of torn paper.

Krylon Workable Fixative is the brand I currently use. I’ve seen online that this is described as being available in Matte or Gloss, which is incorrect. Their Matte Finish (#1311) is not workable. Get the one with “Workable Fixatif” #1306 on the label, which is described as “gloss” but I don’t notice that except on graphite or charcoal pencils, and even then it’s more “satin” than “gloss.” The fumes are very strong, so you must use this in a well-ventilated area, and keep the work there for 10-15 minutes until it completely dries. If you work on thin paper, the drying resin in the fixative can cause the paper to curl, so tape it down or press it flat as it dries. Grumbacher is another brand of workable fixative, and comes in a matte finish.

FYI, Daler Rowney has a fixative called Perfix that also comes in liquid form in a jar. The benefit of that is that you can go old-school and use a mouth atomizer to apply your spray. That takes some practice to get used to, but you should try it if you want to avoid the fumes from a spray can. Perfix is a final, not a workable fixative, however.

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One last thing, if you use charcoal to sketch on a canvas before painting in oil, you can use a fixative to prevent the oils from mingling with the charcoal. Be sure and only use a “workable” fixative in that case, and notice that the oil layer may dry a little more slowly than usual.

Links:
Krylon Workable Fixatif
Grumbacher Workable Fixative
Daler-Rowney Perfix
Mouth Atomizer at Dick Blick store