Some surfaces will be easier to paint with acrylics if prepared first.
Acrylic paints are popular because they are fast-drying, water-based and have a variety of thicknesses or "viscosity." They are enjoyed and employed by both beginning and expert painters and can be used on many different surfaces. Many types of paper or canvasses designed for artists' use are already prepared for accepting the application of acrylic paint. However, if you're using raw canvas or a surface other than pre-prepared paper or canvas, you may need to prepare and test the surface before applying paint.
Instructions
Preparing Surfaces
1. Raw canvas may need an application of medium or gesso before painting.
Prepare raw canvas surfaces with Liquitex gloss medium and varnish, matte medium, matte gel medium or acrylic gesso. Use the medium if you want the canvas color to show through or use the gesso to create a flexible, non-yellowing white background for your painting. Apply gesso to the canvas after it is stretched to ensure a tight surface; one layer is usually enough, but you can apply additional layers to create a smoother surface. Apply the medium with a paintbrush, or apply the gesso with a brush, painting knife, trowel or airbrush depending on the texture of painting surface desired.
2. Paper can be prepared with medium or gesso.
Prepare paper with the same steps as you would for canvas; again, use the medium if you want the paper color to show, or gesso if you want a whiter surface. Tape the paper firmly to your easel, board or other hard surface before applying medium or gesso to prevent warping and allow it to dry completely before painting with acrylics.
3. Slick surfaces may require sanding before painting.
Prepare metal or glass if it is very shiny with 400-grit sandpaper. Cleanse the surface thoroughly so it is free of dust, dirt or grit before applying paint.
4. Sand only the area you want to paint.
Prepare slick Plexiglas or plastic by sanding the surface; if you want to preserve the transparency of the surface, sand only the areas you are going to paint.
5. Colors will be most accurate after preparing with gesso.
Prepare wood by sanding it for smoothness, cleansing the surface so it's free of dirt, dust and sawdust, and applying two to three coats of gesso.
Unusual Surfaces and Testing Surfaces
6. Test unusual surfaces to make sure they are compatible with or will hold the acrylic paint.
7. Apply some paint to the surface and let it dry for at least 72 hours. Wait longer if your weather is humid.
8. Use a sharp knife to score or dent the painted surface in a crosshatch pattern.
9. Place masking tape over the painted/scored surface and rub it firmly, making sure it sticks evenly over the painted surface.
10. Remove the tape slowly; if there is paint on the tape, then the surface does not have good adhesion. Solve this by using a different surface preparation or selecting a different surface to work on.
