Yep sanding it down with fine grade wet&dry helps.

Done it many a time.:crying:

Common sense, but do make sure the old painting’s at least a year since the last stroke was placed, as if it’s not sceintifically dry you’ll be painting lean over wet. In a year’s time even the old picture’s final glazes (if there were any) should be dry.
Of course, if you don’t mind the new picture, in time, potentially cracking, go for it.

Once I did this and painted over a portrait (note: no impasto, no large visible brush marks in the portrait!) – needless to say from some angles the “shadow” of the portrait’s head was clearly visible! So maybe not a great idea if your work is anything like fine. In fact only do it if you’re totally skint (as I was at the time). It’s one of those mistakes you only make once – or should only make once. Putting a knife blade through a finished painting is another you only do once! Buy new canvas, it’s not that expensive.

Best wishes,

nw

I was once asked by a student to show him a shortcut to being able to draw like the best Japanese cartoonists whom he admired. I had to tell him that they only got that good by hard graft, obsession and talent. None of which my student possesed.

nw

Whats this got to do with sanding down a perfectly good already stretched canvas?

RTO
Just sand it down and hold it up to the light in different angles to see if its flattened the oils thats already on it.

Whats this got to do with sanding down a perfectly good already stretched canvas?

Baron, Its bad English – a round about way of saying don’t take short cuts. Canvas is cheap, cheap, cheap.

nw

Also be aware that oil paints become transparent with time. You may think you’ve painted over it opaquely but years down the road a “ghost” image may appear. You sometimes see this on the old masters, where they have changed a composition.

I have changed some elements of a painting a year later. I read some technical advice once to rub down the surface with lacquer thinner first before painting on old paint. It softens it up and gives some tack, making the new layer adhere better.

It’s not all about cost, a previously painted surface can be nice to work on if prepared properly.

True enough. Possibly? X-rays reveal many old masters have overpainted earlier works, succesfully. But that doesn’t mean they didn’t do it for economic reasons, or just from sheer laziness, or for fraudulent reasons (passing off old stock for new). And it doesn’t mean that many paintings haven’t disintegrated because of this.

I would still advocate buying a new canvas. If you like the experience of painting over old paintings, then prepare your new support to give you that experience.

There’s nothing more disheartening than having a good painting flake away, from an earlier one below. It happens! It’s happened to me. I’m probably not the only one! Do you want to risk it?

Best wishes,

nw