Common seat sizes include 20" x 20" x 2" and 20" x 20" x 4", thicker deep-seat options around 25" x 25" x 6", and much larger papasan-style cushions listed at roughly 47–67 inches in one dimension (exact sizes vary by style).
Many cushions advertise waterproof or water-resistant performance, along with fade- and UV-resistance. Some listings also mention stain resistance and mildew resistance, or fabrics designed to let water bead and roll away.
Common attachment methods include sewn-on ties or string ties, anchor straps, and rope-style belts that secure cushions to frames and help prevent slipping.
Many replacement cushions arrive vacuum-compressed or vacuum-packed. Listings typically recommend allowing about 2 hours or more for the cushion to recover its shape, and some suggest using a hair dryer on low to speed the process.
Care instructions most often recommend spot cleaning or wiping clean. Some cushions also feature removable covers or zipper closures to make laundering or cleaning easier.
Some listings sell single seat cushions, while others offer multi-seat packs (examples include 2- or 4-piece seat sets). Other sets include both seat and back cushions together; one example lists a 25" x 25" x 6" seat with matching back cushions at 31.5" x 25.5" x 7".