12pk sharpies: http://www.amazon.com/Sharpie-Chisel-Permanent-Markers-36201/dp
sold by amazon for $5.99. Might be listed in more buying choices on the
side.
Experience two markers in one with the revolutionary twin tip permanent
marker
Features a fine point tip for thin, detailed lines on one end and a chisel
point tip for both broad and fine line widths on the other end
Larger marker allows for a super large ink supply
Quick-drying ink is waterproof, smear proof and fade-resistant
Set of 12 Black Markers
