A throw pillow insert is the plain form that goes inside a decorative cover. Most are polyester fiber in an 18 by 18 inch square. Fill weight, cover fabric and how well the insert keeps its shape matter more than anything else.
The six sets below are all 18 by 18 inch inserts in packs of four. Fills, covers and weights come from each product’s listing page. We have not used these inserts ourselves. Allergy wording is the makers’ own and we do not repeat it as fact.
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What to Look For
| Feature | Why it matters |
|---|---|
| Fill weight | More fill gives a fuller look |
| Cover fabric | Cotton and tight weaves keep fill in |
| Size | 18 inch insert in an 18 inch cover is flat; 20 inch looks fuller |
| Care | Check machine-washable and dryer instructions |
Specs at a Glance
| Set of 4 | Fill | Cover | Notes |
|---|---|---|---|
| EDOW | Down alternative microfiber polyester | Polyester | 0.99 lb (450 g) each; medium support; machine washable |
| Obruosci | Polyester | Microfiber and polyester | Vacuum packed; fluffy and ultra soft |
| Amazon Basics | Down alternative fiberfill | Polyester, 180 thread count | 4-pack; machine washable |
| Foamily | Down alternative | 100% cotton | Firmer, rounded shape; true 18 x 18 fit |
| Oubonun | Polyester (3D fill) | 100% cotton | Square; for covers and shams |
| LANE LINEN | Polyester | Polyester, 120 thread count | Medium firm support |
The 6 Best Throw Pillow Inserts
1. EDOW Throw Pillow Inserts, Set of 4
Four 18 by 18 inch inserts, 0.99 pounds each, filled with microfiber polyester that the maker calls medium support and machine washable.
Suits: a standard, fuller insert. Strengths: a stated weight per insert. Weaknesses: polyester cover. Skip it if you want a cotton shell.
View EDOW Throw Pillow Inserts Set of 4 Lightweight Down Alternative Polyester Pillow on Amazon
2. Obruosci Luxury Pillow Inserts, Pack of 4
Four 18 by 18 inch inserts in microfiber and polyester, vacuum-packed so they arrive compressed and fluff up.
Suits: a plush, soft fill. Strengths: vacuum packaging. Weaknesses: allergy claims are the maker’s. Skip it if you want firm.
View Obruosci Luxury Pillow Inserts Pack of 4 18 x 18 inches on Amazon
3. Amazon Basics Throw Pillow Insert, 4-Pack
A four-pack of 18 by 18 inch down-alternative fiberfill inserts in a 180 thread count polyester cover, sold as machine washable.
Suits: a simple store-brand set. Strengths: a clear pack. Weaknesses: few extra details. Skip it if you want cotton.
View Amazon Basics Throw Pillow Insert Down Alternative Fiberfill 18 x 18 on Amazon
4. Foamily 18×18 Throw Pillow Inserts, Cotton Cover
Four true 18 by 18 inch inserts of down alternative in a 100 percent cotton cover that the maker says holds a firm, rounded shape.
Suits: a crisp, full look. Strengths: a cotton cover. Weaknesses: firmer than plush inserts. Skip it if you want a squishy pillow.
View Foamily 18×18 Throw Pillow Inserts Set of 4 100 Cotton Cover White on Amazon
5. Oubonun 18×18 Pillow Inserts, Cotton Cover
Four polyester-filled inserts with a 100 percent cotton cover, sized for covers and shams.
Suits: a cotton-shell insert. Strengths: a cotton cover. Weaknesses: few details. Skip it if you need fill weights.
View Oubonun 18×18 Pillow Inserts Set of 4 100 Cotton Cover Square Throw Pillow Insert on Amazon
6. LANE LINEN 18×18 Pillow Inserts, 4 Pack
Four polyester-filled inserts with a 120 thread count cover and a medium-firm support the maker describes.
Suits: a medium-firm insert. Strengths: a stated firmness. Weaknesses: a low thread count. Skip it if you want a tighter weave.
View LANE LINEN 18×18 Pillow Inserts 4 pack Medium Firm Support Loft white on Amazon
Care Tips
- Fluff and shake inserts to restore loft.
- Wash only as the label allows and dry fully.
- Pick an insert about 2 inches larger than the cover for a fuller look.
- Store spare inserts in a breathable bag.
Mistakes to Avoid
- Using an insert smaller than the cover.
- Skipping fluffing after unpacking.
- Washing without checking the label.
- Buying inserts without checking the cover size.
Throw Pillow Insert FAQ
What size insert for an 18 inch cover?
An 18 inch insert is flat. A 20 inch insert gives a fuller look.
Are these machine washable?
Several listings say yes. Check the label.
The Short Version
For a stated weight, the EDOW. For plush vacuum-packed inserts, the Obruosci. For a simple store brand, the Amazon Basics. For a cotton shell and a firm shape, the Foamily. For another cotton option, the Oubonun. For medium firm, the LANE LINEN.
