"Can you wash it" is the wrong first question — "what's inside it" is. The fill material is what actually determines whether a weighted blanket is machine-safe, hand-wash-only, or something in between.
Almost every weighted blanket can technically be washed. The real question is whether it can go through a normal cycle without the fill clumping, shifting, or splitting a seam — and that comes down entirely to what's providing the weight. Here's how the three common fill types actually differ once they hit water.
Identifying Your Fill
Check the care label first. If it's missing or worn away, feel the blanket through the fabric: a fine, sand-like texture that moves smoothly is almost always glass microbeads. A slightly grainier, more granular feel with visible small round shapes is usually plastic poly pellets. A dense, gritty texture that barely shifts is likely sand — and sand-filled blankets are the ones to treat most carefully.
Glass Microbeads
This is the most washer-friendly fill available. The beads are small and uniform enough to redistribute evenly through the stitched pockets during a spin cycle, so they're far less likely to clump in one corner. A cold, gentle machine cycle is generally safe, provided the total wet weight stays under your machine's limit.
Plastic Poly Pellets
Poly pellets are larger and lighter than glass beads for the same weight, which means more volume is packed into each pocket. That extra bulk is more prone to shifting and clumping under a hard spin. A gentle cycle still generally works, but hand washing is the safer default if the blanket is older or the stitching feels worn.
Sand-Filled Blankets
Sand-filled weighted blankets are the exception — most manufacturers explicitly advise against machine washing these, since wet sand is significantly heavier than dry sand and can strain seams well beyond a machine's design limits. A duvet cover that's washed separately, with the sand-filled insert spot-cleaned only, is the standard approach here.
Where This Fits
The Weighted Gravity Blanket · Slate uses glass microbead fill specifically because it's the fill type that holds up best to regular washing — no separate cover required, no sand-related restrictions. The Nightfall Weighted Eye Mask is filled the same way, for the same reason.
Weighted Gravity Blanket · Slate
6.8kg, glass microbead fill, 152 × 203cm — the washer-friendly fill this piece is about.
Shop the BlanketNightfall Weighted Eye Mask · Dusk Violet
Same glass microbead fill, scaled down for the face — pairs naturally with the blanket.
Shop the Eye MaskThe right fill means the ritual doesn't get harder to keep up over time.
Full care instructions live on the Weighted Gravity Blanket · Slate product page.
Frequently Asked Questions
Is glass bead fill actually safer to wash than plastic pellets?
Generally yes — the smaller, more uniform bead size moves through the fill pockets more evenly during a spin cycle, which reduces the risk of clumping in one section.
What happens if you wash a sand-filled blanket by accident?
It won't necessarily ruin it immediately, but the added weight of wet sand puts real strain on the seams. If it happens, lay it flat to dry rather than lifting it by one edge, which concentrates the extra weight on a single seam.
Can you tell the fill type without a care label?
Usually, by feel — fine and smooth points to glass beads, granular and slightly bulkier points to plastic pellets, dense and gritty points to sand. When in doubt, hand washing is the safer default for any fill type.