It is the upper face during forming, and on a Fourdrinier it keeps more fines and filler than the wire side, so it is usually smoother and slightly brighter. The name comes from the press felt that picks up and carries this face after the couch. Many printing specs and lab reports default to the felt side unless both sides are required.
Heard on the job
Felt side reads 92.1 and wire side 91.3, a normal split for this machine.
Also heard as
- top side
- FS
Related terms
Wire side
Face of the sheet that lay against the forming wire while the sheet was formed.
Two-sidedness
Difference in properties between the two faces of a paper sheet, such as color, brightness, gloss or texture.
Felt
Endless fabric that carries the wet sheet through the press nips and absorbs the water squeezed out of it.