The invention relates to a partially-soluble cross-linked starch which is characterised in that it is cross-linked using a carefully-selected cross-linking agent. The invention is also characterised in that, when dispersed in water at 20 °C, the starch has: a partial solubility that is at most equal to 20 %, preferably between 0.5 and 15 % and more preferably still between 1 and 10 %, said solubility being measured using test A; a Brookfield viscosity of between 500 and 5000 mPa.s at a concentration of between 10 and 20 % dry matter (% MS); and a particle size, measured according to laser diffraction particle size, such that, in terms of volume, 50 % of the particles have a size less than 60 µm and at least equal to 10 µm and preferably a size of between 10 and 30 µm. The invention also relates to a film-forming composition which is characterised in that it contains at least one such partially-soluble cross-linked starch. The invention further relates to a material-bonding method which is characterised in that it comprises at least one step involving the inventive film-forming composition. In addition, the invention relates to a bonded material obtained using the aforementioned bonding method and to the use of the partially-soluble cross-linked starch for the bonding of materials.