Medium Density Overlay, MDO
Found in hardware stores, this sign painter’s material provides proven stability.
Although you can draw or paint directly on the MDO panel with oils, watercolors, or dry drawing media, we recommend a barrier for most applications.
When painting with any acrylic paint, medium, gesso, or ground, we recommend applying 2 or more coats of Gloss Medium first to reduce support induced discoloration.
For oils, apply 3 or more coats of Acrylic Gesso or Fluid Matte Medium to reduce oil absorption.
Grounds (including those for drawing media and watercolors), gels, and pastes can be applied to alter the surface’s absorbency, durability, or texture.
Article: Medium Density Overlay
Tech Page: Surface Preparation