The Peco Pro Grass Static Grass fibers are particularly fine and specially coated to conduct a static charge. The colors are designed to be layered one at a time to give the modeler the desired depth and 3D effect. You have to think a bit like a painter, building up the scene layer by layer, blending colors and fiber lengths to replicate nature. Seasonal colors, natural colors and even fine white snow fibers in multiple lengths suitable for N, HO and larger scales are available, all designed for use with Peco Pro Grass Static Grass Applicators.