You need to measure your cushion, write the measurements, leave 5/8” for seams and sew up 3 sides. The 4th side you may want to insert a zipper so you can wash it or just stitch up the 4th side and wash in your machine.
For the amount of work it would take you should use outdoor fabric. Bed sheets will mold and rot out by the end of the season. Need to use water and sun resistant fabric. Used old cushion covers as your pattern.
This is just for inspiration, but this lady uses old duvets to make outdoor chaise covers, but she does live in an arid, sunny climate, and she probably brings the cushions in every night. http://artandsand.blogspot.com/2017/04/thanks-to-blogging.html
I agree that you should use outdoor fabric!!! HOWEVER there is a way to turn regular fabric into outdoor fabric. Look at this spray product called Thompsons fabric seal...https://www.thompsonswaterseal.com/waterproofing-products/small-projects/waterseal-fabric-seal. You might do fine with spraying the bedsheets with this waterproof spray. Only spray the already cut to size fabric. You will need at least a few heavy coats I would think to turn sheets into an outdoor fabric. The only thing I would be worried about is if the bedsheets would be thick enough to use as a fabric cover for outdoor cushions! Maybe get a thicker outdoor fabric for the cushions and use the bedsheets as outdoor pillows. Just a thought but hope it all helps! Good luck!
You need to measure your cushion, write the measurements, leave 5/8” for seams and sew up 3 sides. The 4th side you may want to insert a zipper so you can wash it or just stitch up the 4th side and wash in your machine.
For the amount of work it would take you should use outdoor fabric. Bed sheets will mold and rot out by the end of the season. Need to use water and sun resistant fabric. Used old cushion covers as your pattern.
This is just for inspiration, but this lady uses old duvets to make outdoor chaise covers, but she does live in an arid, sunny climate, and she probably brings the cushions in every night. http://artandsand.blogspot.com/2017/04/thanks-to-blogging.html
I agree that you should use outdoor fabric!!! HOWEVER there is a way to turn regular fabric into outdoor fabric. Look at this spray product called Thompsons fabric seal...https://www.thompsonswaterseal.com/waterproofing-products/small-projects/waterseal-fabric-seal. You might do fine with spraying the bedsheets with this waterproof spray. Only spray the already cut to size fabric. You will need at least a few heavy coats I would think to turn sheets into an outdoor fabric. The only thing I would be worried about is if the bedsheets would be thick enough to use as a fabric cover for outdoor cushions! Maybe get a thicker outdoor fabric for the cushions and use the bedsheets as outdoor pillows. Just a thought but hope it all helps! Good luck!