Where can I purchase “old-fashioned” single piece foam, (not memory foam) standard bed pillows?”
This may not be exactly what you are looking for- but by old-fashioned, I think of the poly-foam filling. But what I’m finding is not a single cut piece. Kmart has a few options (including Martha’s Grandma’s line!)– Good luck! Also, price wise you should find options between $11-20/pillow. Anything above that for a standard size is probably getting into composite (fake down, gel, memory foam).
