Uni Walton line (solid colors) of Armstrong Linoleum is made two thicknesses: 0.100 in. (2.5 mm) and 0.125 in. (3.2 mm = 1/8"). I do not know if this is available in the USA and/or Canada.
If anyone knows a north american retail source of this material in 3.2mm thickness in black (UP280) and in tan/brown (UP260), please post that information.