Liquid chalk markers come off easily with a quick wipe from a damp cloth. The markers are touch dry within just a few minutes and will stand up to very light rain for a short period before starting to dampen and run. Not suitable for windows suscepitble to condensation. Available in various sizes and a large range of vibrant colours, these markers are perfect for prodcuing a great range of results from intricate works of art, to simple frequently changing signage. Ideal Surfaces: Use on any non-porous surface including black and white boards, glass, metal, ceramic tile and other smooth surfaces.