Prismacolor markers are low in odor, alcohol based , permanent ink markers. Prismacolor markers have 2 tips, one broad and one fine and a single ink reservoir for perfect color match, end to end The broad tip features 3 different drawing angles for a total of 4 different drawing widths. They come in a full range of 156 colors,including 3 full range of grays, and metallic. The metallic markers are single tipped , broad or fine. Prismacolor marker sets come in assortments of 12 gray tones, warm, cool, and french(blue-ish).