Vir Campestris wrote:
I've got to the point where I'm considering painting the ply cladding in
my new man cave (completion is in sight - we're wk20 of a 12wk build,
doubtless due to all the rain we had this year)

Will ordinary emulsion work? Will it need thinning the way it does on
new plasterboard?

Andy
Being water based it will raise the grain to differing degrees depending
on the quality of the ply.
L'd dilute the emulsion about 10% - any more and it will very messy to
apply.

Allow to dry fully and de-nib it with 180-240 grit then a full strength
coat maybe two depending on the quality of the paint.