Aldehyde resins with reduced and stabilized free-formaldehyde content

In a process for preparing a low formaldehyde crosslinking additive wherein a ketone and formaldehyde are reacted in a molar ratio of 1 mole of ketone to about 2 to 5 moles of formaldehyde under aqueous alkaline conditions at about 20 to 80.degree. C. to obtain a water-soluble ketone-formaldehyde condensate containing about 1 to 4% by weight of unreacted formaldehyde and wherein at least an effective amount of hydrogen peroxide is added to said condensate to react with the unreacted formaldehyde present therein and allowing the reaction to proceed at about 60 to 100.degree. C. at a pH of about 3.0 to 6.5 until the unreacted formaldehyde is reduced to less than about 0.4% by weight of the condensate, the improvement comprising further treating the condensate by adding an effective amount of urea or dihydroxyethylene urea to provide a stable free formaldehyde content.