Can you use oil over latex?
Mineral oil destroys latex. Other oils are not good for latex.
You can paint matte paint over semi-gloss paint as long as they are the same base, i.e. oil over oil, latex over latex, or oil over latex and the surface is clean and dulled either by sanding or chemical deglossing. If the semi-gloss is oil and you are painting latex matte, then use an oil based primer as a bridge first.
You can always paint latex ( water based )over an oil based paint as the latex just dries on the surface. However don't paint an oil based over a latex paint. Oil based paints need to absorb into the wood or other surfaces or it will just dry and flake off. For more information on the differences and when or not to use a latex or oil paint please see the following article. . http://www.ehow.com/how_4713170_between-latex-oil-base-paint.html
You should never paint an oil based paint over a latex paint. Oil based paints are meant to absorb and dry into the surface. If you were to paint an oil based paint over a latex based paint it would simply dry and flake off. For more information on when to use a latex or oil based paint please see the following article. http://www.ehow.com/how_4713170_between-latex-oil-base-paint.html
You will have no problem painting satin over top of flat paint. Just remember to use the appropriate paint that will stick to the old coating. If the old coating is latex (water based) you can go over it with latex or alkyd (oil based) paint. If the old coating is oil based you can only go over it with oil based paint or a hi performance latex that is specialy made to go over…