The Original Artisan's Effect Wine Glass Markers Luminous 4 pack replace Wine Charms with reversible 4mm tips (bullet or Chisel) use on Glass Ceramic Metal Chalkboards Plastic. Use on wine glasses for party's wedding or just for fun. Use on All types of Surfaces, Glass,Chalkboards, Ceramic, Plastic. Metal. Also Ink is non-toxic and conforms to EN-71 and ASTM D4236 Each box contains 4 great color's pink, green, yellow and purple The ink washes off easily with warm soapy water Brightest and Boldest Wine Markers Available. Sourced with Extra Bright Japanese Ink. and Tips.