The Sketchmarker Brush Pro markers feature professional Japanese alcohol-based ink, which is fast drying and permanent. Sketchmarker has a 400 color palette, more colors than any other alcohol marker on the market! Refillable ink is available in all 400 colors, with enough ink volume for approximately 12 to 14 refills. Markers are twin-tipped with replaceable brush and chisel nibs. Markers are certified and meet safety and quality standards: European - ASTM D-4236 (LHAMA Certification), American - EN71-3.