An RMA crosslinkable composition for making thick coating layers having at least one crosslinkable component comprising reactive components A and B each including at least 2 reactive groups wherein the at least 2 reactive groups of component A are acidic protons (C—H) in activated methylene or methine groups, and the at least 2 reactive groups of component B are activated unsaturated groups (C═C), to achieve crosslinking by Real Michael Addition reaction, the composition further including a base catalyst (C), an X—H group containing component (D) that is also a Michael addition donor reactable with component B under the action of catalyst C, wherein X is C, N, P, O or S and a sag control component (E). A crosslinkable composition is also disclosed for preparing thick coating layers having a dry thickness of at least 70 mu having a surface appearance and hardness of the resulting cured composition.