The construction of the board determines its conservation ability which does not change just because it is not wrapped. However unprotected boards will mark and scuff easily so I would leave well alone. I would think that hobbycraft sell standard board.
Send me a pm and lets see if I can be competitive via mail order.
David – I don’t want to step on Pat’s toes but Mitrecraft in Lincoln deliver to Manchester on Tuesdays. They do conservation mountboard, Art Bak, acid-free tape, and much more, in any quantities you want. Orders over £80 are free; under is £6 delivery. Ring them on 01522 511322