I sell a product that I've named Unicorn Sequin Pillow Cover. Did I write it correctly? It is a pillowcase made from sequins with unicorn printed on it.
If the sequins have unicorns printed on them, then yes.
If the unicorn is made of sequins then it is a Sequin Unicorn Pillow Cover
We start with “pillow cover”, or “pillow case”. A cover of a pillow. We then assign the property unicorn to the pillow cover. “unicorn pillow cover”. Then we assign the property sequin to the unicorn. “Sequin Unicorn Pillow Cover” (and put it in title case).
I've seen "Sequins Mermaid Pillow Case", for instance. Which "sounds" quite right, a.k.a. doesn't make anyone's ears bleed. I believe it's all about following some kind of substance/attributes hierarchy as to order the terms. So, if I'm on the same vibe as in my example sentence, I think I'd rename this item you're about to sell, namely: Sequins Unicorn Pillow Cover.
Wishing you sweet deals.
Yes, that name is fine.
If you were trying to describe the product, it would be better to use something less ambiguous. All people will know from the name is that the pillow cover features sequins and unicorns in some way. They won't know how heavily the sequins feature, or whether the unicorn is made of sequins, printed on, or the shape of the pillow itself.
But unless your customers are the kind of sequin/unicorn devotees that will buy anything that features them, they are going to want to look at a picture before purchasing anyway.
It could be argued that the ordering of the words makes it sound like the unicorn is made of sequins, or the sequins have unicorns on them, but to me these seem like results of reading the name as if it is part of a sentence, rather than just a name. In a product name, regardless of the exact structure of the product, it could make a lot of sense to put the "Unicorn" (presumably the most distinguishing characteristic) at the start as you have done, particularly if there are other types of "Sequin Pillow Cover" in your inventory.