Prismacolor KIT-3533-12 Set of 12 Prismacolor Colorless Blender Art Markers Creates a variety of line widths by increasing (or decreasing) pressure and twisting the barrel. Brilliant, permanent ink and four line widths from one double-ended marker Unique four-in one design creates four line widths from one double-ended marker. Brilliant, permanent ink and four line widths from one double-ended marker