The present invention relates to a radiation-polymerizable mixture which includes a polymerizable compound, a polymeric binder which has units of methacrylic acid, a methacrylic acid ester and a styrene, the latter in a proportion of 40 to 65% by weight, a finely divided mineral pigment on a silicic acid or silicate basis, a photopolymerization initiator, a compound having at least two epoxy groups in its molecule and a thermal hardener for epoxy groups. The mixture is advantageous, in particular, for producing solder masks and can be cured after exposure to an image and development by heating to about 80.degree. to 150.degree. C. to form a stencil which is resistant under soldering conditions.