Yes, they are injection molded. I asked Gibson and I think it's ok to say this. I mold parts for Gibson.
That being said, please, don't anyone even think about trying to get me to sell to them directly.
I just ran several Hummingbird pickguards. The engraving is in the mold and somewhere on this site
is a picture of the lady that hand paints them. I call that color filling ( I also do laser engraving)
and we color fill all the time.