Acrylic mediums, and Up to my Knees, daily painting by Everglades artist Jo-Ann Sanborn

Up to my Knees, 2014, Jo-Ann Sanborn

acrylic on board, 7"x5"

Here's some information I'd written a while ago about acrylic mediums and never posted. I don't really like using them, because they feel a bit sticky to me, but have tried quit a few and insist my acrylic students do, too. 

I don't like working with mediums as they make the paint feel someone sticky or "plastic, but they do have some important uses to consider.  For those who like the paint to stay opened longer, a little medium is terrific.  It is also good for extending paint into large areas of the canvas, like some skies.  The most important reason to use a little now and then is to increase adherence.  This is especially important when you are using it with a lot of water.  A ratio of 50% water can cause the paint not to adhere properly, and just a little medium will ensure it stays in place. 
 

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, the same thing that holds the pigment together in your paints, and can act as a colorless paint.  Acrylic medium is works very well for glazing transparent or opaque paint, and can also be used as an isolating and protection layer on a finished painting. 

There are a number of gels 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. 

Additives, as opposed to mediums, do not contain binders, and  should not be overused without consideration for adherence.  After all, you want to make sure your textures last long into the future.  Using a little medium with the additive can extend your options while still being sure that the quality remains high. 

If you’re an acrylic painter, learn as much as you can about the additives available for your use.  Liquitex, my favorite brand, provides a handbook with detailed information about they’re mediums and additives.  This Guide can be read online or downloaded.