Abstract: A mixture of at least two compounds each having at least two double bonds, said mixture having a WFR from 200 to 600 g/mol of double bond and at least two of said compounds each comprising at least two (meth)acrylic esters as double bond component, WFR being given by: ? i = 1 n ? ? i ? MW i / Z i = WFR ? ? where ? ? i = 1 n ? ? i = 1 ?i is equal to the molar fraction of compound (i) in said mixture, n is equal to the number of compounds in said mixture and n is ?2, Zi is equal to the number of double bonds in said compound (i), MWi is equal to the molecular weight of said compound (i).