This incredible gel ink pen writes, then dries to a 3-dimensional, opaque, matte, pastel color line! Patented gel ink for creating raised effect. 1.0mm ball diameter for bold 0.7mm line effect. Water-based, odorless, gel ink formula. Waterproof on many surfaces. For best results, use on non-porous, clean, smooth surfaces. For use on dark or light surface background. Meet ACMI non-toxicity standards (AP seal).