Mould-release agent composition in the form of an emulsion comprising: (a) at least one reactive polyorganosiloxane comprising at least two silanol ≡SiOH groups per molecule; (b) at least one crosslinking agent having at least three ≡SiH units per molecule; (c) at least one non-reactive linear polyorganosiloxane oil which is a linear homopolymer or copolymer which has, per molecule, monovalent organic substituents, which are identical to or different from one another, bonded to the silicon atoms, and which are chosen from the group consisting of C 1 -C 6 alkyl, C 3 -C 8 cycloalkyl, C 6 -C 10 aryl and C 7 -C 15 alkylaryl radicals; (d) from 0.1 to 20 parts by weight of glass beads as spherical amorphous filler; (e) at least one surfactant; (f) optionally at least one additive chosen from the group consisting of: a film-forming polymer, a complementary lubricant, an anti-friction agent, a coalescence agent, a wetting or dispersing agent, a mineral filler, an antifoam agent, a thickener, a stabilizer, an acidifying agent, a biocide and an antifungal agent; (g) optionally at least one dehydrocondensation catalyst; and (h) water; the amounts of surfactant(s) and of water being sufficient to obtain an oil-in-water emulsion; characterized in that the composition of the glass beads is as follows: - the silicon content expressed as SiO 2 is less than 63% by weight, - the calcium content expressed as CaO is greater than 20% by weight, - the sodium content expressed as Na 2 O is less than 2.9% by weight, - the aluminium content expressed as Al 2 O 3 is between 0.5% and 15% by weight, - the boron content expressed as B 2 O 3 is between 0.2% and 2.5% by weight, - the potassium content expressed as K 2 O is between 0.35% and 1% by weight, and - the magnesium content expressed as MgO is between 1% and 4% by weight, relative to the total weight of SiO 2, CaO, Na 2 O, Al 2 O 3, B 2 O 3, K 2 O and MgO. (a) at least one reactive polyorganosiloxane comprising at least two silanol ≡SiOH groups per molecule; (b) at least one crosslinking agent having at least three ≡SiH units per molecule; (c) at least one non-reactive linear polyorganosiloxane oil which is a linear homopolymer or copolymer which has, per molecule, monovalent organic substituents, which are identical to or different from one another, bonded to the silicon atoms, and which are chosen from the group consisting of C 1 -C 6 alkyl, C 3 -C 8 cycloalkyl, C 6 -C 10 aryl and C 7 -C 15 alkylaryl radicals; (d) from 0.1 to 20 parts by weight of glass beads as spherical amorphous filler; (e) at least one surfactant; (f) optionally at least one additive chosen from the group consisting of: a film-forming polymer, a complementary lubricant, an anti-friction agent, a coalescence agent, a wetting or dispersing agent, a mineral filler, an antifoam agent, a thickener, a stabilizer, an acidifying agent, a biocide and an antifungal agent; (g) optionally at least one dehydrocondensation catalyst; and (h) water; - the silicon content expressed as SiO 2 is less than 63% by weight, - the calcium content expressed as CaO is greater than 20% by weight, - the sodium content expressed as Na 2 O is less than 2.9% by weight, - the aluminium content expressed as Al 2 O 3 is between 0.5% and 15% by weight, - the boron content expressed as B 2 O 3 is between 0.2% and 2.5% by weight, - the potassium content expressed as K 2 O is between 0.35% and 1% by weight, and - the magnesium content expressed as MgO is between 1% and 4% by weight,