When formaldehyde-free cellulose crosslinking agents are screened to eliminate those having toxicity, odour and environmental problems of their own, the most likely candidates are seen to be polycarboxylic acids and 1,3-dimethyl-4, 5-dihydroxy-ethyleneurea (also known as DHDMI). These differ in cost and effectiveness, and will require further research and development to become fully practical.