Polyken 221 Premium Duct Tape is the #1 Premium Screen Block tape in the market. It is Ideal for silk screening and a variety of other demanding applications. These include: screen blocking of frames in the screen print industry and a variety of other applications such as, waterproof packaging; Container sealing; media-blast protection; sealing white pre-formed duct joints; sealing tape for sidewall building materials; and sealing flex duct connections. It is highly conformable and its aggressive solvent-resistant adhesive provides clean removal from frames and a variety of other surfaces.