For painters who enjoy the strong, fast-drying qualities of acrylic, you can always make acrylic earth paint that is more luminous than tube acrylics because there are no fillers or preservatives.
Ingredients: acrylic medium & earth pigment
Prep time: 3 min. per color
Combine 1 part acrylic medium and 1 part pigment by placing the medium on your palette and carefully adding the pigment.
For more opacity, add more pigment. Store paints in airtight containers. Thin with water.
Any clear acrylic medium from any art supply store (liquitex, Golden, etc.) will do.