A quick question on underpaintings, mediums, and paint consistency

[Flatuloso]

Hey folks,

I'm working on a few large scale images that are going to take a good amount of time to complete, so I'm going to be painting them indirectly, with monochrome underpaintings followed by several layers of color, with varying transparency.

I'm fairly familiar with the general rule of fat over lean. However, I'm a little muddled as to how I need to apply this rule to the method of painting that I've found myself comfortable with. Allow me to explain.

I've found that as I begin a painting, and at some stages down the road, I like painting really, really thin. For putting down that initial drawing my preference is to work with real soupy paint that's easy to pull off the canvas, and I really like the quality of mark you can get starting a painting this way. Furthermore, when I go back to dried layers, I usual prefer to wash a transparent general color over an area and then work into it with paint of varying thickness. Now, from what I've heard about thinning paint and cracking, etc. I am led to believe that this method of painting will lead to trouble, however I have seen other artists do it, so I'm hoping that it's just a matter of what mediums you choose to use when mixing down your paint. So now for my questions...

1. On this initial drawing, is it a real bad idea to thin the paint down with medium as opposed to turpentine? I like the consistency you get with medium more than that of turpentine, however this would mean that the very first layer of paint is largely medium, and should go over the painting LAST, right? By the way, the medium I'm using is a turp/stand oil mixture, about 4:1 or so.

2. I've pretty much avoided using straight turpentine to thin paint altogether, and so the color washes I lay over older layers are thinned with medium, which I paint into with thicker paint as desired - is this going to give me trouble?

3. Though I'm familiar with the rule of fat over lean, I still don't think I understand it fully. I know that plenty of paintings are painted in multiple sessions, and they seem to have aged pretty well, yet it's also apparent that the paint consistency is fairly thin. I've heard of artists glazing down and then painting up a piece up to dozens of times, are their glazes getting thinner and thinner with each progressive attack, are they using different mediums, or am I just fretting over nothing?


That's about the extent of my questions, I'll make sure to post these things when their done as payment for any help I receive. Thanks guys!

[arttorney]

It's not just about cracking, there's also sinking to worry about. Do you notice the paint seems duller when it is dry than it was when you put it on?
does this ever happen in patches?

Maybe use tempera or acrylic for painting underneath. (If these are large scale on canvas, rather than a panel or something, I think I'd lay off the tempera. ) It sounds like you go through some rather complicated steps sometimes and I would think it could get really hard to remember how fat or lean the last thing you put on was without keeping an extensive log. (What a lot of work that seems to be.)

[timmyhol]

Hi,
I think if you let the paint dry fully between each painting session you should have no problems. If the paint was really think I would give it a good length of time to dry out, at least a week some might say months, but usually I find thats just not practical. I wouldn't use medium in layin but often use it in the next session and paint on-top the next day or week. Some people add a drying medium as well to help with this. I wouldn't worry about the paint sinking in as you can apply a varnish at a later stage to unify everything, again for that you have to wait until everything is really dry, best to leave it 6 months or so. Hope this helps.
Tim

[dcorc]

If you are painting in physically thin layers, then a few days drying time between layers is all thats needed (as a general rule of thumb, give it twice as long as it takes to become touch-dry before doing the next layer).

The aim of "fat over lean" is to ensure that successive coats tend to get more flexible, rather than less flexible, and slower-drying rather than faster-drying. There is a lot to be said for minimising the amount of medium added to the paint (keep total additions to less than 20% - and less is better).

Don't paint with turpsy washes - though you can use turps alone to just slacken the paint off a little to a fluid-creamy consistency, particularly in earlier stages. And don't add loads of medium in later stages. Add just enough to change the paint-handling.


Dave