All About Fabrics
My advice when looking for a slipcover fabric is to think neutral colors for a classic & timeless feel. Solids are great as you can always add interest & color with contrast cording, trims or pillows! Durability, fade & stain resistance are other important factors. The best choices would be medium or med-heavy weight upholstery/ home decor/ & outdoor (100% solution dyed acrylic) type materials.
I do work with a handful of fabric trade vendors and I'm happy to show you swatch books that could meet your needs! There are very few options for retail fabric store locations on eastern Long Island. If you wish to shop online that's a convenient option. Most sites offer samples you can purchase. I highly advise getting the samples so you're 100% sure of the color/ texture/ weight before ordering the yardage for your project.
Here's a few: