JCPenney Special Run
#410174 Stablemates Parade of Breeds - Draft Horse, Bay Roan
While I wouldn't call this horse 'bay', I do consider him a beautiful example of Breyer's modern masking technique. Not too long ago, markings and patterns were the products of free-hand airbrushing or a metal stencil clamped over the model. Both techniques had their limitations and could produce some less than satisfactory results.
Masks for modern models are essentially stickers which are applied to the appropriate areas of the model. For white markings, the stickers are applied to the bare (or sometimes white base-coat) models before spraying the model with the body colour.
These stickers are created digitally and printed by the dozens. This technique allows for complex and delicate markings which were too time consuming or technically difficult for mass-production with the old techniques and a uniformity which was once difficult, if not impossible to accomplish. Sadly, the stickers do reduce the number of variations in a run, but sticker placement and colour can vary and sometimes patterns are altered (usually to simplify them) later on in the run.