The invention relates to crosslinkable materials based on organopolysiloxanes. Said materials are characterized in that in addition to organopolysiloxanes they contain at least one low-molecular organosilicon compound with 2 to 17 silicon atoms comprising units of the formula (I) R1aR2b(OR3)cSiO4−(a+b+c)/2, R1, R2, R3, a, b and c having the meaning given in claim 1 provided that low-molecular organosilicon compounds comprising units of the formula (I) where b is 0 have at least one unit of the formula (I) in which a is 0 or 1, and at least one unit of the formula (I) in which a is 3.