I would use thick foam rubber cushions and wrap them in high loft quilt batting. If you can get it, buy Sunbrella fabric for long lasting, no fading, no mildew cushions. (Just a little shameless plug for my employer - and yes, I do have an affiliation but it is a wonderful fabric for outdoors and now indoors too!)
Teresa

I would use thick foam (you can shape with an electric knife) wrapped in quilt batting, slide on your fabric cover and make fabric covered buttons. Atach your buttons through the batting and foam with a long needle. Then you can add extra stuffing if it's not puffy enough.

Are all of these filler recommendations suitable for cushions that are exposed to rain? I know the sunbrella fabric can hold up, but will the filler dry without problems?

Thanks so much for the help! It was the wrapping it in batting part that I didn't know about! (and I know Sunbrella is the best!)

I think the foam rubber and batting would eventually dry and could be hung on a line or set out in the sun to help speed the drying. It would be better all around if you can get to the cushions and bring them under cover before they get rained on. Also, it's not a good idea to put Sunbrella in the dryer on high heat.

I am looking for replacement cushions for furniture made by Island Collection. I have looked at Erwin & Sons web page...they cost more than the furniture when new!

Thanks!