Acrylic paint can sometimes act as a glue that sticks caps to tubes; making them difficult to remove. For these moments Golden offers the GRIPR .GRIPR is excellent for those sticky cap situations and for artist with diminished manual dexterity or strength. The Flexible ABS plastic tube opener makes removing difficult caps simple. It works with new and old 2 and 5 oz. tube cap designs for Golden Acrylics, Williamsburg Oil, and QoR Watercolor tubes as well as similarly sized paint tube caps of other brands.