What kind of paint should i use to paint my wooden varnished window sills white?

I have bought silk emulsion can i use that?What kind of paint should i use to paint my wooden varnished window sills white?
in our experience, it is very difficult to paint over stain or varnish. It must be sanded or removed in some manner firstWhat kind of paint should i use to paint my wooden varnished window sills white?
I painted over our varnished wood trim %26amp; doors--there was alot of it %26amp; I wasn't about to sand it so I used b.i.n primer/sealer on it first--worked great
to do it the right way....





you would need to lightly sand the surface with 300 grit sandpaper or sanding block. then use tack cloth to get rid of all of the particles that may be on the surface. then unless you know if that varnish was oil or water based-you should use a latex based primer. DO NOT USE KILZ. use bullseye/zinsser/1-2-3 primer which can be found at lowes and most paint places. this primer is latex and is made for projects like this. this primer is made to dry in one hour. after the primer dries you want to paint it with a latex 100%acryllic paint. lowes has valspar paint which i would recommend-semi gloss or high gloss. if you get the high gloss it is formulated to self level so you a have a professional finish with no brush marks.