Reveal liner? If you were doing it in plastic -
http://www.plaslyne.co.uk/pages/cillsetc_internalwindowboards_revealliners.htm
I think most reveals are plasterboarded unless you've got shutters. Or damp.
well im just a painter & decorator / ames taper but i am pretty dang good with the carpentry only thing i get mixed up with is what things are called...........
and yeah most windows now the ingos are plasterboarded to cut out costs because its alot cheaper to plasterboard than to put facings and wooden ingos in well thats the way in scotland anyway
englands ways are alot diffrent like alot of plastering is done there and none here its ames taping which is cost effective =]