Provided is thermosetting urea-formaldehyde (UF) resin binder formulation, preferably prepared with modified styrene-maleic anhydride. The formulation has a viscosity in the range of from 3 to 10 cP and a surface tension of from 35 to 50 mN/m, and is prepared using a UF resin composition exhibiting a viscosity of from 175 to 250 cP.