Good afternoon, Any ideas as to what this is? I have a few seedlings with leaves that look like this. I checked with a magnifying glass and could find no insects or webs. They are growing indoors under lights and a fan runs 24/7.
TIA, Joe

If this were on an orchid leaf, it would be edema due to (probably) overwatering.

That was my thinking also, but perhaps that's because we just read about it in the orchids forum.