Saturday, September 11, 2010

More about drying in.

I will return to the posts on color soon. I get e-mail questions and I thought I would answer a few of those.

Dear Stape;
What makes some colors shiny and others matte after drying? I've noticed that some colors really shine and others are like a tiny layer of black hole sucking in available light. These is especially apparent when looking at the painting from the side. Is it medium, mixing, type of paint, ground? I read you said that Liquin could make it matte. Is that the only cause? Humm. A coat of varnish takes care of business but then everything is homogenized. I would love to learn to control this for it to do my bidding rather than my painting looking like a blotchy hot mess unless varnished.
signed; Matte

Dear Matte;

You have probably had the experience of working in watercolor and as the water evaporated the colors dulled. To some extent the same thing happens to oils. When the surface loses its sheen, less light is bounced back to your eyes and the colors appear dulled. Varnishing restores that sheen to the surface and the painting looks like it did when you painted it. This problem is called "drying in" and has a number of causes. They are:
  • an overly absorbent ground. Try an oil primed linen, that might help.
  • Some colors are more prone to drying in, Black, burnt umber and dark colors in general. Some pigments are able to suck up great quantities of oil. When that oil drops into the layers below it, you have a dried in spot.
  • painting with thinner rather than a medium, there are lots of mediums but I use alkyds. Liquin gives a satin finish, Galkyd gives a gloss, and walnut oil-alkyd gives a very glossy finish. Varnish and oil mediums will help too, although I think they are more prone to drying in than alkyd.
  • some drying in is probably unavoidable, it is just a part of oil painting. But it is easily remedied.
  • Even if it is not dried in today, it will almost certainly dry in a little over the next year. So retouching a painting is a good idea anyway. Down the road you will want to get a real coat of varnish on it. Then the problem should be over.
There are a number of ways to bring back the gloss on the surface. If the painting is still wet, shoot it with retouch from a can or a mouth atomizer. Go easy, use too much and the painting might melt. Perhaps that is what happened to you. Used carefully this shouldn't happen. Don't put on so much that the varnish pools on the surface. Give it little thin coats so it dries quickly.

If the painting is dry, you have a number of options. You can polish the surface sometimes with a cloth or a pair of Ryan Seacrest's old nylon stockings. You can also "oil out" the painting. Put a small amount of linseed oil on a lint free cloth and put a very thin coat of oil on the pictures surface. Make sure the painting is completely dry first though. You don't want to smear those little spots of cadmium yellow that you thought were dry. You can also do this with Liquin or Galkyd, but remember, that is not a final varnish!


Gregory Becker said...

I have a painting that is a flemish still life and because I used the umber and darker colors in transparent or semi transparent mixtures it dries much more evenly. But I have another problem. It has sat too long between layers and the next layer of paint is not sticking to it. What can I do to get the surface to grab the paint again? Linseed oil just rolls off it. I tried cutting an onion in half and rubbing that on the surface and it only worked a little and only in some areas mostly the lights.
Great post Stape said...

HI Gregory,
You can either rub the painting down with real turpentine, softening the paint but possibly removing some paint or use a re- touch varnish. That 's what it is made for, wiping down a painting to re work or re touch.

On my last experiment using only primary, secondary and tertiary colors; all I can say is that you don't miss your neutrals until you can't paint with them.

I did make use of tone , tint, value , saturation..all that. Maybe if I used Judy's definition of tertiary , I might have had something interesting. The other way to do it is to have two pigment color wheels, one with cool primary colors qinacradone, ochre, ultramarine. And warm primaries, cad red, cad yellow, and cobalt or pthalo and use both of them.

That worked out better but that is not true color theory. That is testing out painting theories.

Richard J. Luschek II said...

What are your thoughts on that retouch varnish in a can. I use it when I need to freshen up a painting.
So far so good.
I only had one issue when I sprayed and it was very cold and the retouched fish-eyed, which then resulted in a stream of obscenities.

Debra Norton said...

We called it "sinking in" in school. I was taught to solve the problem by brushing on retouch varnish. We put it on very thin, using a brush, and wiped the brush with a paper towel before dipping into the retouch again, to keep the retouch and the painting clean. When I do this I always look at it from other angles in addition to straight on to make sure it's not pooling anywhere. And if I find a spot that smears, I work on it very carefully.

Most of the time I paint the smooth style Stape talked about in the last post, so this method works pretty well for me. I've also switched to an oilier (is that really a word?) paint for my worst "sinker inner," raw umber, and it seems to have helped a little, but not gotten rid of the problem completely.

I've thought about spraying, but haven't tried it yet.

I do enjoy your blog Stape, it takes me back to talking around the lunch table at art school.

Stapleton Kearns said...


I think that retouch varnish is where I would start. In the Gammell days we would sometimes rub a painting with a cuttlebone to take the surface down a little bit. cuttlebone is one of those squid anatomy thingies they put in parakeet cages.

Stapleton Kearns said...

You are a brave colorist and mentally well organized to do this.

Stapleton Kearns said...

I think retouch in a can works just fine.I sometimes use a mouth atomizer though.

Stapleton Kearns said...

Spraying works on work that is still damp.

Brad said...

Thanks Stape! I will try to grab my 'drying in' by the horns and ride it to intrinsic beauty.