Melamine-urea-formaldehyde resins may be prepared using processes including a first cook stage, a second cook stage, and a final addition wherein: the molar ratio of formaldehyde to urea and melamine (F:U+M) in the first cook stage is from about 2.0 to about 5.0; and the molar ratio of formaldehyde to urea and melamine (F:U+M) in the second cook stage is from about 1.5 to 3.0; and the molar ratio of formaldehyde to urea and melamine (F:U+M) in the final addition from about 0.4 to 0.70.