Which of these words refers to commercially manufactured writing materials?

My mother taught me how to distinguish the 2 different spellings - "e" = as in letter. The hint above is even better.

Bone, I don't know why some people downvoted your comment. You're right. The two words are indeed related.

JellyBaker, My Mother taught me "er" as in paper; "ar" as in car

JellyBaker, stationary is with an A...first letter of the alphabet..not moving...stationAry

I can never remember the different between stationary and stationery 😔

They are actually related. Prior to retail businesses being in fixed locations everything was sold in markets. This changed when in university towns sellers of paper, books, pens etc started up the first shops. Their business was no longer mobile but stationary

whew, that was a close one, had to think a minute...