Sixpence stamps were common postage stamps in Britain and the British colonies during the 19th century and were in circulation into the 1900s. Values differ for the stamps based on the condition of the stamp and the specific stamp. Older stamps, like the Victoria stamps, are more valuable than more recent ones, like the King George V. While collectors can still find sixpence stamps for sale, there are also forged stamps on the market. Knowing how to identify the real thing will save you from paying money for a fake.
Look at a stamp catalogue to compare your stamp to the stamp image. This will help you determine the colour and design of an authentic sixpence stamp.
Look at the stamp. The first identifying marker of sixpence stamp is word “Sixpence” along the bottom of the stamp. Some stamps also say "6d," but all sixpence stamps have the word “sixpence” written on the stamp.
Pay attention to the image on the stamp. The image is usually a good indication of a fake sixpence. Images differ based on the when the stamp was issued. For example, the 1871 Victoria sixpence stamp was blue and featured a profile of Queen Victoria. The Fiji sixpence stamp was a simple stamp reading "6 Pence" without any picture. In most forgeries, the picture looks odd in some way, such as inaccurate sizing.
Look at the paper the stamp is printed on. Paper that is too thick or the wrong colour is the most likely mistake for stamp paper.
Consider the perforations on the stamp. The perforations on the stamp are another way to distinguish a forgery from the real article. Perforations running along the bottom of the stamp were usually around 12 to 13 indentations on the sixpence stamps.