A urea preparation comprising 5% to 75% by weight of one or more urea components having a molecular weight of ≥ 350 g/mol and containing at least one urea group, 15% to 95% by weight, preferably 30% to 80% by weight, of one or more organic solvents from the group of the N-alkylamides which have a molecular weight of 155 to 700 g/mol, are free of urea groups and have the following general formula: in which (a) R 1 is a hydrocarbyl radical containing x = 1 to 24 carbon atoms, R 2 is an organic radical containing y = 1 to 12 carbon atoms, and R 3 is an organic radical containing z = 1 to 12 carbon atoms, or (b) R 1, R 2 and R 3 are as defined under (a), but R 1 and R 2 are bonded to one another by a chemical bond and together, with inclusion of the C(=O)N group, form a ring having 4 to 10 ring atoms; and, in the case of a ring having 4 or 5 ring atoms in which x + y < 4, the R 3 radical contains at least 6 carbon atoms and at most 11 carbon atoms or (c) R 1, R 2 and R 3 are as defined under (a), but R 2 and R 3 are bonded to one another by a chemical bond and together, with inclusion of the nitrogen atom in the general formula, form a ring having 4 to 10 ring atoms, with the proviso that, for each of (a), (b) and (c), x + y + z ≥ 8, 0% to 35% by weight of one or more organic solvents other than which do not contain any urea group or any ionic group and have a maximum of two heteroatoms selected from the group consisting of nitrogen and oxygen, and 0% to 50% by weight of a salt which differs from the urea component (s), the solvent (s) and the solvent(s), and where all percent by weight figures are based on the total weight of the urea preparation. 5% to 75% by weight of one or more urea components having a molecular weight of ≥ 350 g/mol and containing at least one urea group, 15% to 95% by weight, preferably 30% to 80% by weight, of one or more organic solvents from the group of the N-alkylamides which have a molecular weight of 155 to 700 g/mol, are free of urea groups and have the following general formula: in which (a) R 1 is a hydrocarbyl radical containing x = 1 to 24 carbon atoms, R 2 is an organic radical containing y = 1 to 12 carbon atoms, and R 3 is an organic radical containing z = 1 to 12 carbon atoms, or (b) R 1, R 2 and R 3 are as defined under (a), but R 1 and R 2 are bonded to one another by a chemical bond and together, with inclusion of the C(=O)N group, form a ring having 4 to 10 ring atoms; and, in the case of a ring having 4 or 5 ring atoms in which x + y < 4, the R 3 radical contains at least 6 carbon atoms and at most 11 carbon atoms or (c) R 1, R 2 and R 3 are as defined under (a), but R 2 and R 3 are bonded to one another by a chemical bond and together, with inclusion of the nitrogen atom in the general formula, form a ring having 4 to 10 ring atoms, with the proviso that, for each of (a), (b) and (c), x + y + z ≥ 8, (a) R 1 is a hydrocarbyl radical containing x = 1 to 24 carbon atoms, R 2 is an organic radical containing y = 1 to 12 carbon atoms, and R 3 is an organic radical containing z = 1 to 12 carbon atoms, or (b) R 1, R 2 and R 3 are as defined under (a), but R 1 and R 2 are bonded to one another by a chemical bond and together, with inclusion of the C(=O)N group, form a ring having 4 to 10 ring atoms; and, in the case of a ring having 4 or 5 ring atoms in which x + y < 4, the R 3 radical contains at least 6 carbon atoms and at most 11 carbon atoms or (c) R 1, R 2 and R 3 are as defined under (a), but R 2 and R 3 are bonded to one another by a chemical bond and together, with inclusion of the nitrogen atom in the general formula, form a ring having 4 to 10 ring atoms, 0% to 35% by weight of one or more organic solvents other than which do not contain any urea group or any ionic group and have a maximum of two heteroatoms selected from the group consisting of nitrogen and oxygen, and 0% to 50% by weight of a salt which differs from the urea component (s), the solvent (s) and the solvent(s), and