In reply to sbc23:
> This is a bit OCD, but someone will know.
Glad you asked
The folder supplied with the latest Climb Shetland Miniguides is 230mm although the guides themselves are A5 (210mm).
The largest extant guidebook
IS the Lancashire brick - 217mm.
The BMC 1999 Peak Limestone Wye Valley two volume guidebook and the 1996 Cicerone Cornish Rock guidebook are both 216mm.
The Jingo Wobbly Climber's Handbook to England & Wales is 215mm.
The 2003 SWMC Gower & SE Wales guidebook is 213mm.
Out of the rest of the current UK guidebooks around a quarter are now A5 (210mm), the bulk of which are portrait format although perhaps there are half a dozen bouldering and sport guidebooks in A5 landscape format.
There is then another fifth between 190-200mm comprising SMC & Presda Press at 200mm and the BMC & YMC at 192/190mm.
Around one in six are 178mm (or 174mm with card covers) including the latest CC & Cicerone guides.
After A5 the next most common size still comprising nearly quarter of UK guides is 170mm produced by the FRCC and Ground Up and previously by the CC & YMC.
A few of the older SMC guidebooks at 165mm have not been replaced and then there are a handful at other sizes including the Rockfax Pockets format at 148mm and some Cordee guides of various non-standard sizes.
HTH