The early Sadler teapots were "Brown Betty" style, tall and shaped more like a coffee pot with possibly a marking found on the bottom. For a Sadler teapot made between 1899 and 1937, there will be an impressed mark that reads "ENGLAND JSSB." For a Sadler teapot made after 1937, there could be an impressed or printed mark that reads "SADLER BURSLEM ENGLAND."
James Sadler and Sons Ltd. was founded in 1882, so there are early teapots made between 1882 and 1899 without any markings. These early "Brown Betty" teapots were made from a fine red clay found in the Stoke-On-Trent area of Britain. The teapots were then covered with a dark brown glaze. This "Brown Betty" style teapot made the company well-known. The company later added teapots that featured scenes, landmarks and people of the United Kingdom, as well as mugs and tea accessories.
For any Sadler teapot made after 1947, several different printed marks were used. One mark reads "SADLER MADE IN STAFFORDSHRE ENGLAND." Another mark reads "SADLER MADE IN ENGLAND." A third mark reads "JAMES SADLER MADE IN ENGLAND SOPHIE CHINTZ." Antique Sadler teapots can be found online, from collectors, at estate sales, flea markets and even yard sales.