Lee Stopple, a noted photographer, took this image of Mathewson and the similar image of Home Run Baker also in this collection. The clarity and composition of the photos is of exceptional quality and we can get a sense of Stopple from the accolades he annotated on back.
Christy Mathewson poses in his plaid coat in Galveston, Texas in March 1912. The Giants were in town to face the hometown Galveston Sand Crabs for a Spring Training exhibition match. The plaid coat was one of his favorites and there are several images of him wearing it during this period.
The full story of the 1912 Stopple Galveston baseball postcards see here: