I always get tons of questions about which size pillow insert works best with our handmade covers. Since it's sort of a long answer, I thought it would be best to do an in depth explanation and share some of my favorite sources for inserts.
We've tried different methods to give the best universal fit when making pillow covers and have found a professional fit sizing method to be the best! Guess that's why they call it professional ;) This sizing method is common in designer pillow covers. It involves making the pillow cover slightly smaller (by ~1") than the stated dimensions. This sizing method gives the covers a snug fit over the insert for a full volume look. If the cover is larger than the insert, the cover looks misshapen and can wrinkle easily.
So, for example, when you purchase a quality cover made with professional fit sizing in a 14"x14" size, the cover will be ~13"x13".
Types of Inserts
Pillow inserts generally come in two fill options, down and polyfill. Down is my absolute favorite since it gives the covers a soft fullness and is comfy while snuggling on the couch but can be easily fluffed for a neater, more uniform look. If allergies are an issue, down may not be a suitable option. I recommend purchasing a size up for down inserts. For example, when purchasing a down insert for an 18"x18" cover, a 20"x20" insert is recommended.
Polyfill or down alternative inserts are made with a synthetic material that generally has a firmer form but can become worn and at times flattened or misshapen with frequent use. If purchasing a polyfill or down alternative insert, I recommend purchasing one that has a small zipper closure so that you can add or remove the polyfill as needed. I recommend purchasing the same size as stated on the cover when using polyfill inserts. For example, when purchasing a polyfill insert for an 18"x18" cover, an 18"x18" insert is recommended.
My favorite pillow insert is the IKEA FJADRAR inner cushion. It's available in 20"x20", 16"x26" and 26"x26".
If you need other sizes, I've ordered inserts from Comfy Down on Amazon and have been very pleased. These are Made in the USA!
Other sources include JoAnn Fabrics, Hobby Lobby and Walmart. These stores usually have coupon codes available so don't forget to check out their websites and apps for deals! Another option is to buy clearance or discounted decorative pillows at TJMaxx or Home Goods with a zipper cover and just remove the cover and use the inserts. I've done this quite a few times!
It's also important to remember that not all pillow inserts are created equal. Some inserts are very full, while others may be very thin. The good news is that when you find the right insert...the possibilities are endless! Changing out covers for each season or for different trends is a great inexpensive way to refresh your home decor!
We are hoping to offer inserts for our covers in the near future and are looking into all of the logistics to make that happen. In the meantime, I hope this post was helpful! If you have any favorite sources or tips for buying pillow inserts, please leave a comment below.