Chartpak Products - Chartpak - Press-On Vinyl Letters & Numbers, Self Adhesive, Black, 1/2"h, 201/Pack - Sold As 1 Pack - For signs, posters and equipment identification. - Self adhesive vinyl will stick to most clean, dry surfaces. - Can be used indoors or outdoors. For signs, posters and equipment identification. Self adhesive vinyl will stick to most clean, dry surfaces. Can be used indoors or outdoors.