Seal Lock® Plus is an alcohol-based flat coating that stops bleeding on plaster, wood, metal and masonry. It is ideal as a replacement for pigmented shellac, although it does not contain shellac. Seal Lock® Plus may be used as a primer for porous wallboard, plasterboard, drywall and plywood; as a sealer for “hot plaster”, patches and spots, asphalt coatings, plaster walls, wood, multicolor finishes, and metal; and as a stain blocker for creosote, asphalt, crayons, ink, redwood and cedar. Applicable for interior or exterior use. For exterior use, spot prime only. Seal Lock® Plus is also suitable for use as a vapor barrier [perm rating of 0.3].