Cellulose acetate lamination and polyester film encapsulation are often viewed as competing techniques for strengthening deteriorated paper. The author examines the two techniques based on 20 years' experience in institutions where both have been employed, discussing the advantages and disadvantages of each, and the factors influencing the choice of one or the other. Each appears to provide a good measure of preservation when applied correctly and used on appropriate material, but neither should be viewed as the ultimate answer to paper preservation.