I have two squares of neoprene rubber as non-slip mats.
Needing a larger area, I bought a large piece off of a metre-wide roll. On arrival, instead of the slightly tacky shiny finish of the smaller mats, it has an oily residue over its entire surface, both sides, and is matte in appearance. Have I bought different materials or is the newer larger piece "unfinished"?
If unfinished, how would I go about preparing it to have similar non-slip qualities as the older, smaller pieces? I have considered washing it in soapy water in hopes the residue is only on the surface, but not sure if this is the correct or wise approach.