Mediums are produced from natural resins (Dammar gum, Mastic gum) or synthetic resins (acrylic), oils and solvents. They allow the work to be cohesive and favor its longevity. Mediums can change the consistency and the appearance of the finish by giving it a transparent, matte, satin or gloss appearance and also increase the tack of the painted surface allowing additional layers while painting Plein Air.