The canonical make (eponym, if you prefer) of adhesive tape in the UK (cf. Durex in Australia and Scotch tape almost everywhere else). In its original form, shiny and impossible to write on except in ballpoint, and awkward to tear. The name is just a derivative of "cellophane tape" tweaked to make it trademarkable; it was first used when Colin Kininmonth and George Gray licensed the process from the French company CIMA in 1937. The Sellotape Company still operates under that name, but is now a subsidiary of the multinational Henkel Consumer Adhesives.
generic-man informs me that "seroteepu" (セロテープ) is also the generic word for sticky tape in Japan. The company also claims to be the market leader in Ireland and New Zealand.