Yes, you can paint flat paint over satin paint as long as the surface is properly prepared and primed.
If you want to turn your satin paint into flat wall paint simply mix one to one. One gallon of flat to each gallon of satin. The flat wall paint will obliterate any sheen the satin once had.
If you have the satin, you can add flat paint and take some of the sheen off. This would have to be done before application. It will never be a true flat though.
Add a little talcum powder to the paint.
No, you can dull satin or semi-gloss but not the reverse.
semi gloss
Yes, as long as you have the same base that's not a problem.
Yes or it can be the same as the wall paint if it should be flat.
Satin is lower gloss than semi-gloss paint. Paint finishes in order of decreasing gloss are: * Gloss * Semi-gloss * Satin/Low sheen * Flat Some manufacturers call Satin/Low sheen finish Eggshell, and others regard this as a finish between Satin/Low sheen and Flat paint. The higher the gloss finish the easier it is to clean, the higher its durabillity and the more it shows surface imperfections.
If you mix a flat and semi-gloss 1:1 you should end up with a paint in the eggshell range. Mix the same paints 1:3 and you should end up with a satin. Experiment with small amounts to get the desired gloss.
Satin is lower gloss than semi-gloss paint. Paint finishes in order of decreasing gloss are: * Gloss * Semi-gloss * Satin/Low sheen * Flat Some manufacturers call Satin/Low sheen finish Eggshell, and others regard this as a finish between Satin/Low sheen and Flat paint. The higher the gloss finish the easier it is to clean, the higher its durabillity and the more it shows surface imperfections.
Yes, enamel paint will go over flat paint.
Do you realize that you can get FLAT ACRYLIC PAINT. Flat paint refers to the gloss level. You may want Gloss, Satin, Lowsheen or Flat. Acrylic paint on the other hand refers to what the paint is based on or what binder is being used. Acrylic paint is also refered to as waterbased paint. You most likely are referring to putting flat acrylic over lowsheen or gloss acrylic. In answer to your question - as long as they are both acrylic than you will not have any problems. I am in this answer assuming that you are referring you house paints. If not than the same principle applies - acrylic over acrylic is fine. To keep acrylic from going glossy just don't polish it.