Dark ground

Hello everyone. I was wondering if I could trouble someone to help me with another question I have about oil painting. I currently use a pre-primed white canvas and then stretch it on wooden bars. I would like to experiment with different colour grounds. Can I apply a dark ground to a pre-primed canvas and if so, how do I do it? Or is it necessary to apply the ground in the priming? I am a little confused.

Thank you for your help in advance. I hope one day to be able to offer advice myself.

Yours ever,
Arthur Banks

[Karin Wells]

If you are starting with a pre-primed white canvas, you have a surface with Gesso on it.

This gesso can be either acrylic based or oil based. If you have an oil based surface, you can only apply more oil based gesso or paint. If your pre-primed white canvas is acrylic based, you can choose to apply either an acrylic based or oil based substance. The rule here is never apply acrylics over oil...

If I understand your question, I assume that you are asking about the "imprimatura" i.e., a toned/colored surface on the canvas before you begin to paint.

I like to use an imprimatura on my acrylic primed linen. Sometimes I use a prepared colored gesso (Holbein) and sometimes I simply wash raw umber (acrylic or oil) over the white surface. I do not recommend that you ever add color to wet gesso.

Thanks for your help Karin. That was exactly what I wanted to know.

Yours ever,
Arthur

[Debra Jones]

I am not a very smooth surface sort of gal, but I love throwing just color into the Utrecht Acrylic gesso I paint over my canvases. I will splash a few colors, sometimes brazenly onto the surface, just to give variety and kill the white.
Mixing acrylic with acrylic, why would you say not?

I stroke very loosely so I retain the variations of color in the final surface. I know mine is a technique difference, but is there a techical or chemical problem doing this?

My need for color may be because I think a lot like a pastel painter when I do oils and miss the bright pastel papers.

[Karin Wells]

The reason why I suggested that you don't add color to wet white gesso is that it takes a LOT of color to make a darkish tint. I believe that most imprimaturas are somewhere in the neighborhood of a 35% to 50% value.

If you add too much paint to gesso, you alter or break down the properties of gesso. Gesso is different than paint and serves a different purpose in painting.

I think it would be especially problematic if you plan to apply this "altered gesso" to raw cotton or linen canvas.

However, you're probably OK if; you're just tinting the gesso, it is not on the first layer, and the proportion of paint to gesso isn't too high...

[Debra Jones]

That makes perfect sense.