Jo Sonja's Retarder Mediums are used to slow-down the drying time of acrylic paints. Jo Sonja's Retarder Mediums do not reduce paint viscosity and are used for decorative effects like antiquing or thicker colour applications.

Jo Sonja's Tannin Blocking Sealer is ideal for preparing surfaces which are likely to "stain through" paint layers or as a Gold Leaf (real or imitation) Size. This can include knotted wood, stripped furniture and masonite. Jo Sonja's Tannin Blocking Sealer may also be used for pre-sealing items, but should not be used to apply over oily stains.

Jo Sonja's Retarder Mediums are used to slow-down the drying time of acrylic paints. Jo Sonja's Gel Retarder greatly extends drying time and can be mixed with Jo Sonja's Retarder Medium to decrease the "open time," as needed.