Acrylic Mediums and Additives, Everglades Painting by Jo-Ann Sanborn

Big Cypress Morning

My painting today is one that I'm very fond of. We became very close as I worked it over again and again trying to get the look and feel that I wanted of a lovely day in the glades, but more of from a frog's perspective. It hung around the studio for quite a while I became more and more frustrated. One day I decided that drastic change was necessary and got out the big brush. Soon I was "in the zone" and when I stepped back a couple of hours later the painting had evolved to my satisfaction! Sometimes in art, just as in life, you have to let go and let it happen!

Now, for some substance! Acrylic Mediums come in a choice of matte or gloss, and are the consistency of thick cream. They are most usually made of acrylic binder and act as a colorless paint. Using medium can help the paint stay opened longer, economically extend the paint, and increase adherence. Acrylic medium is also perfect for glazing transparent or opaque paint.

Since the medium help binds the acrylic, it’s important to use some medium when thinning the paint. Always use a dab of medium to help the paint bind and adhere if you are thinning the paint with a lot of water. Using acrylic paint and water alone, especially as you get to a 50-50 mixture can affect adherence and a touch of medium solves the problem.

There are a number of gel pastes available for use with acrylics, each with it’s own special use. It’s fun to try these out now and then and when I hold a class I bring a number for students to try. These can act as a binder for another additive, like sand, can thicken the paint to improve the retention of brush marks, and double the volume of paint with little loss of color.

Most additives do not contain binders, and so should not be overused. Another type of additive is the flow aids. These decrease the surface tension, flowing and blending, and open time of the paint, as do the retartders.

If you’re an acrylic painter, learn more about the additives available for use. There’s a wide range of possibilities! Liquitex Paints provide a handbook with detailed information about they’re mediums and additives. This Guide can be read online or downloaded. Golden Paints has some great educational material on their site, too, and their newsletter is full of good information. They've also just come out with a new line of acrylics called "Golden Open", an acrylic with a longer open time.