Chameleon Fineliners are totally unique! They have a patented dual-ink system, with ink in the pen and in the cap, allowing you to create depth, dimension, gradients, highlights, shading and shadows. To instantly blend colors all you have to do is: 1) Switch the Cap (Hold your fineliner in a vertical position and gently place a different color cap on top, clicking it shut); and 2) Blend the Colors (Keep the fineliner in a vertical position for desired blending time). When the Nib Changes Color, remove the pen from the cap. To stack multiple colors, repeat the steps. The fine-point tip gives a super-smooth writing or intricate coloring performance, so write, draw, doodle and color like no other! Water-based, dry safe ink won't bleed through most papers. This Fineliners set contains 12 Chameleon Fineliner pens that create loads of color blending combinations. For ages 6 yrs-teen, from Imagination International.