Most Denby jugs are unmarked. Very occasionally impressed and printed marks are found, sometimes with a date. The printed marks are probably all 20th century. The BOURNE'S WARRANTED mark has only been seen three times - on a 4 oz, a 3 pint and a 4 pint jug and probably dates from the 1840/50s. The "warranted" is from the claim "warranted not to absorb" impressed on early stoneware bottles. (Click button for images)