As my canvas
guys says the thing to look for is 100% Olefin this will survive marine
use even if not a true marine
fabric. Olefin is a man made fibre that is good in outdoor situations. Moisture is a key factor and natural fibres suck. If you can find a reasonable fabric like this it will work well.
guy did some cushions
out of denim for some folks and cursed the whole time he made them. He knew they wouldn't last buut they thought they would save money<g>. Don't use fabric that can't take the environment
For exceptional good looks Sunbrella has serveral fabrics that are woven patterns. They look super expensive but the same price
as plain sunbrella. We did 21 cushions
5 for the cockpit
and the rest below. We did a grey weave pattern with red piping in the cockpit and a grey shell pattern with light background below. This stuff wears like iron and cleans easily. That is what you want! It looks very nice too. Dark colorsdon't look good IMHO.
Last advice is the cushion material. We have thick closed cell foam, 2.5 inches on the seats and 3 inches on the bottoms you can sleep on. The cushions are more than 20 years old and feel like new. Thick closed cell foam is expensive (very) but it lasts forever. It even works as a throwable floatation device but don't throw em they cost so darn much<g>. The cushion counts more than the fabric and costs more than the fabric too. You need deep pockets for all new cushions inside and out.