Tim Holtz Alcohol Ink Hard-Core Art Panels, 3 pk of 4 in. x 4 in. squares. The Tim Holtz Alcohol Ink Hard-Core Art Panel by Ranger is a versatile substrate for fine art and mixed media techniques using Tim Holtz Alcohol Inks, Pearls, Mixatives, and Blending Solution. Hard-Core Art Panels are double-sided vinyl with an Engineered-Wood-Rigid-Core MDF board offering an ideal surface that remains rigid and flat. Vinyl is mounted with a pH non-yellowing permanent adhesive which creates a ready to use bright white, lightly textured surface.