The ink of claim 1, wherein said half-ester of SMA has the structure wherein x is from 1 to 25; y is from 0.1 to 9; z is from 0.1 to 9; n is from 1 to 25; and R is an alkyl, phenyl, alky-substituted phenyl, cycloalkyl, ether, butyoxyethyl or propyl group or mixtures thereof. 4.