A substitute for amino and phenolic resins is disclosed. It is used in the polycondensation of such resins based on formaldehyde for bonding water penetrable cellulosic particles. The substitute comprises an aqueous solution of(a) either at least one aldehyde together with at least one amide and/or together with at least one phenol, or a non-resinous condensation product of formaldehyde and urea, and(b) a sugar or a sugar derivative or their byproducts or a starch or its degradation products or a mixture thereof, and/or(c) a raw and/or treated lignosulfonate.This substitute also reduces the free formaldehyde of the resulting board without impairing the other properties thereof.