Can you put full size mattress on futon frame? - Quora
8 Best Futon Mattresses For Sitting & Sleeping (July 2023 Edition)
YOSHOOT Futon Mattress, Padded Japanese Floor Mattress Quilted Bed Mattress Topper, Extra Thick Folding Sleeping Pad Breathable Floor Lounger Guest Bed for Camping Couch (Gray, Single) : Amazon.co.uk: Home & Kitchen
The 9 Best Futon Mattresses
Futon - Wikipedia
Cotton Rich Standard Futon Mattress for futon frames – Cambridge Futons