Whats a good permanent fixative for oil paint?

[rblitz7]

Does anybody know a good permanent fixative for oil paint on canvas?

[Elwell]

Oil paintings get varnished, drawings get fixed.
When the paint is touch dry, you can put on a coat of retouch varnish.
Once the paint layer is totally dried through (a few months to a year, depending on thickness), a final picture varnish can be applied.
Both natural resins like damar and synthetics are used, and can be brushed on or sprayed.

[fixx]

What 'e said.
You can mix liquin in your paints instead of oils, make it dry faster, but I hate the stuff. Foul muck. Dries the paint in a few days (or as dry as oils get).
Just don't use shellac or something like that. It'll crack your picture like itty bitty puzzle pieces.

[rblitz7]

ah yes varnish, thats what I meant. Its been two weeks since I finished so its dry to the touch.
So I apply something like this first...
http://www.dickblick.com/zz015/10/
...let it dry and then apply this?
http://www.dickblick.com/zz015/65o/
Do I choose gloss, matte, or regular? this is the painting
http://img87.imageshack.us/img87/6457/oilportraitix3.jpg

[Seedling]

You don't *have* to varnish oil-pantings. You can if you want to, but it's optional. :-)

[arttorney]

That was my first thought too. The paint itself becomes fixed. the process is complicated but after the touch dry part at two weeks there is a one year period where the expansion/contraction is at a different rate from the first two weeks. Then after the first year, the painting has kind of settled in for the long haul. If you are going to retouch though, remember fat over lean.

The varnish is kind of in the nature of a protection coat in case you do something really really wrong. You aren't planning on rubbing a lot of sandpaper on your painting, are you?

[Elwell]

There are two reasons to varnish...
1. To unify the surface. As oils dry, areas painted with different pigments and/or mediums can dry glossier or more matte than others. If working in multiple sessions, this can make color matching difficult. Retouch varnish is formulated to even out gloss without leaving a thick varnish layer. Because the film is so thin, it shouldn't interfere with the paint curing, but it also isn't thick enough for...
2. Protecting the painting. Final varnishes are formulated to form a barrier that keeps dirt etc. from becoming embedded in the paint layer. Over time, if the varnish becomes dirty and discolored, it can be removed and replaced without (hopefully) disturbing the paint underneath.

[rblitz7]

thanks for all the great replies! well, I think my teacher wanted me to varnish because he said it brings out the richness of the colors, like the darks darker and the reds redder. Is this correct?

[arttorney]

I never varnished one of my paintings, but those ones down at the museum that I can tell are varnished seem kind of lustrous. If this is the look your professor wants, then I would choose the gloss rather than the matte. Your painting seems to be pretty smooth and so there won't be too much random sparkling from paint ridges all over the place. It'll just look all shiny and new.