Triazolopyridine dyes useful for thermal transfer of methine dyes have the formula ##STR1## where R.sup.1 is C.sub.1 -C.sub.20 -alkyl, which may be substituted and interrupted by one or more oxygen atoms, or is substituted or unsubstituted phenyl or hydroxyl,R.sup.2 is a 5- or 6-membered carbocyclic or heterocyclic ring which may be substituted and benzofused,R.sup.3 is cyano, carbamoyl, carboxyl or C.sub.1 -C.sub.4 -alkoxycarbonyl,R.sup.4 is oxygen or a radical of the formula ##STR2## where L.sup.1 is in each case C.sub.1 -C.sub.8 -alkyl which may be interrupted by 1 or 2 oxygen atoms, andX is CH or nitrogen.