Interactive Paints on top of Solvent Varnish?

[texana6]

I recently pulled a painting out of my closet that I did more than a year ago and would like to work on it again. No, I don't expect the paint to become interactive now that it has cured for so long. The problem is ... I don't recall if I put only an isolation coat (fast medium/fixer) or if I also topped it with Invisible Solvent Varnish. Can I paint on top of the varnish with the IA then do another isolation coat, and then Solvent Varnish again. This is a wrap-around canvas. Is there some way I could do a test on the side of the canvas that would determine whether or not solvent varnish has been applied. Next time I will write on the stretcher bars what I have done!

[Einion]

Originally Posted by texana6

Is there some way I could do a test on the side of the canvas that would determine whether or not solvent varnish has been applied.

Wipe a small area with mineral spirits, leave it for a short while and then see if it's sticky? Spirits should have no effect on dried acrylic so if it becomes gummy or tacky that should indicate that you did use a spirit-soluble varnish.

Originally Posted by texana6

Next time I will write on the stretcher bars what I have done!

Good idea! Amazing how fickle the ol' memory is.

Einion

[jennifervs]

Hello!

Einion's right. Take some mineral spirits, and in a small, unobtrusive place, try to remove the varnish. If you can remove the top coat, than you will know it was varnished! You can then gently remove the varnish in this way. If not, then you know you are safe to paint on top.

The general rule is that oils are applied on top of acrylics, so technically you should not apply an acrylic like Interactive on top of a painting that has been varnished using a solvent varnish. If you were just going to touch up, I think you would be safe, because I know a few art restorers who use acrylics in moderation when they restore old oil paintings.

But as always, test before application!

On my own works, I usually attach a mailing label sticker on the back that is easily removed which lists the medium, date finished (in case of oils) and varnish used. That has saved me in a situation like yours, when I pull out a piece, decide it is not as bad as I thought and want to rework it.