Things You'll Need
Instructions
Measure the height of your Toby jug. Doulton Toby jugs vary in height but rarely exceed 7.5 inches. Miniature Tobies were introduced in 1939 and measure about 2.5 inches in height.
Turn over the jug and find the trademark on the underside. There may also be an artist's signature, which will help date the piece. Doulton marked its wares from the beginning so it is unusual to find a genuine piece that is unmarked in any way.
Make a rubbing of an impressed trademark if you have trouble reading it. Hold a piece of tracing paper firmly against the mark, then rub lightly with the side of a sharpened pencil or crayon. Alternatively, take a photo of the mark with a digital camera and use the camera's software on your computer to increase contrast until you can read the mark.
Inspect the handle on your jug. Early Doulton Toby jugs had plain handles, but after the 1950s the handles were often decorated as part of the design. The Long John Silver jug, for instance, has a parrot for a handle.