1:250 000 Scale Colour Raster is supplied in TIFF (RGB 256 colours) format with LZW compression.
1:250 000 Scale Colour Raster is supplied as an online download from the OS DataHub.
The compressed download file includes (among others):
56 edged-matched individual 100km by 100km tiles aligned to the National Grid.
Product legend in TIFF and PDF format.
1:250 000 scale gazetteer
Ordnance Survey divides Great Britain into squares of 100km by 100km. Each square has a unique two-letter reference, for example, TG in the grid below. 1:250 000 Scale Colour Raster tiles are identified by the National Grid reference of the south-west corner of the 100km2 area they cover.
An introductory guide to the British National Grid (BNG) is available on the OS website.