OFUTON KOBO does not publish a lifespan or a weight limit for HIMARI or SORA. How long either stays comfortable depends on nightly use, body weight, the surface beneath it and how it is cared for. Both are made for nightly use at home on a firm, level surface, and turning, rotating and airing them regularly helps them keep their loft and support.
What changes with use
Every shikibuton compresses gradually as it is slept on, and the filling loses some of its original loft; this is normal settling. It may be time to consider a replacement when you can feel the floor through it, when hollows no longer recover after airing, or when the filling has become lumpy.
How to extend its life
- Turn it over and rotate it head to foot regularly, so the same areas are not always under pressure.
- Avoid leaving it down in the same spot for days on end.
- Keep it dry: fold it each morning and air it every one to two weeks.
- Use it on a firm, level base; a soft or uneven surface underneath lets it sag.
Heavier sleepers
Any shikibuton compresses more under a heavier body, so a firm, level base and regular rotation matter more. If you want more cushioning between you and the floor, SORA 宙 is the fuller option at approx. 12 cm. If you prefer a steadier, firmer surface, HIMARI 日葵 has an approx. 8 cm firm polyester support core.