Gels and mediums can be thought of as colorless paints, as they are composed of the same polymers as acrylic paints. Essentially, they are the "glue" or binder that dry to form continuous, durable films. 

The main property that differentiates a majority of products is viscosity - that is, how thick or thin a product is. This is what actually separates gels from mediums. Mediums are thinner than the gels, which have much higher viscosities. Mediums are thin enough to be pourable, while the gels are not.

Gels and mediums offer a variety of sheens (Matte, Semi-Gloss and Gloss), enabling artists to control sheen in their artwork by blending the appropriate gel or medium with acrylic paints. The typical higher gloss can be reduced by adding any of the matte gels or mediums.

Gels and mediums are also frequently used as a glue for collaging materials together. Gloss products are usually preferred for this purpose, since they offer the greatest transparency; however, the other sheens work just as well as a glue. Generally, we recommend the Soft Gel Gloss for this purpose, although the choice of medium or gel can be as exacting as the artist wishes.

Note: Each manufacturer offers slightly different products and naming conventions. For our purposes we’ll be referring to Golden products, but feel free to experiment with other brands.