When viewed in reflected white light against a black background, transparent films show the classical interference colours of thin plates which permit an estimate of their thickness to be made. When of the order of 100 nm (1000 Å) in thickness they appear white (silver film) and when thinner they appear gradually less intensely white, then grey and finally black., üliõhuke hõbedaplaat, mille interferentsist tulenev värvus oleneb plaadi paksusest ning muutub 100 nanomeetrist allapoole paksuse vähenedes särav-valgest valgeks, seejärel halliks ja lõpuks mustaks