choosing upholstery fabric

Beautifully-patterned fabric matters, but so does durability, comfort, and mildew-resistance.

If re-using foam, the existing foam can be used to make a template but otherwise measuring the space and making templates is necessary.

Durability

"Fabric wear rating is usually expressed in double rubs. Double rubs are found through a mechanized test called the Wyzenbeek Test. The Wyzenbeek Test is regarded as the standard of measuring abrasion resistance for fabric in North America. With this method, a piece of cotton or wire is placed on a special machine and rubbed against the fabric being tested in a back and forth motion along the warp and weft until signs of wear are present." [Source]

Anything rated above 30,000+ double rubs is considered heavy duty and ideal for living rooms or heavily trafficked areas, for boats 50,000+ double rubs is even better.

Looking at the double rub rating isn't the only important factor, there is also fiber content, how often the fabric is used, the fabric's weave, and cleaning instructions that ought to be considered.

Mildew-resistance

To avoid mildew, avoid natural fibers(cotton, cotton blends) and choose synthetics like acrylic, olefin or polyester.

Dust mite sensitivity

If sensitive to dust mites choose a cover fabric that is tightly-woven.[Source], which will keep dust mites from entering the foam. Latex does not keep dust mites out(it only keeps molds from growing inside it).