What do you call this type of embroidery?

Bargello? It is making straight stitches into patterns. Example

Over an already knitted or needleworked piece, it can look like this – keep long yarn and the back looks exactly the same as the front

@Blueroses Exactly what I was looking for—thanks!
Curious…were you already familiar with this or did you just look it up?
(Always looking to pick up some online searching tips as well.)

@Nimis I learned this technique in a textile/art class in high school. I loved the look and I have used it so often! I’m very into old fashioned crafts and bargello originated as the backside of cross-stitch embroidery. When somebody looked at the back and realized that was a great pattern on it’s own!

Edit: it’s very much the same technique when you do pattern beading (like peyote stitch) or weaving

@Blueroses You had a textile class in high school? That’s rad. I wish we had that!
Very cool that it originated as the backside of the cross-stitch.
I’ve always thought the backside of textiles had its own charm.

It’s also called duplicate stitch and is sometimes used by knitters for extra embellishment :)