We carry a large selection of opalescent glass from Wissmach Glass Company. Wissmach opalescent glass is made with a combination of white glass and a cathedral (transparent) color. The opacity of this glass (how much you can see through it) depends on how much white glass was used when it was made. The solids are completely opaque. Wissmach Dense Opal (-D) uses more white than the Light Opal (-L), so it is more opaque, or harder to see through.