I have been experimenting with different types of gloss finishes on acrylic paintings. The ‘gloss medium and varnish’ when poured on, makes interesting unpredictable cracks and texture as it dries. I liked it for a finish on the ammolite paintings (see them in “For Sale – Abstract” on my website.) The added texture in the surface worked well there. However, this method will not make a smooth surface if that is what you want.
Recently I have been experimenting with the ‘pouring medium’. It is formulated to make a level glossy surface when poured on. I tried brushing it on too, but the brush marks do show when it is dry. I recommend pouring it, and then using a drywall putty knife to smooth it for the best chance at a smooth surface. However, it shrinks a lot as it dries, and the first layer simply hugs whatever texture is in the paint. I like that effect, but for a truly smooth surface you will likely need to pour several layers. It still can make the odd crack on larger paintings, and another layer will be needed to repair that. As with all acrylic mediums, avoid continuing to work it as it starts to dry, or cloudiness can result.
Acrylic gloss spray varnishes work too for a glossy thinner finish, but I like to avoid spraying products if possible, for health reasons. Does anyone else have other recommendations about how to make a very smooth shiny finish on an acrylic painting?