1887 was a major year in the development of GB postage stamps with the release of the first bicoloured set of definitive issues in Queen Victoria’s reign.
The lilac and green series
Before the Jubilee issue was released an unpopular range of lilac and green stamps were in use. These used the same colour for multiple denominations. Consequently, to celebrate fifty years of Queen Victoria’s reign it was decided to revamp the entire range. Additionally, advances in printing technology meant that it was possible to produce bicoloured stamps.

The 1887 jubilee issue

In 1884 the Postmaster general formed a committee to look into the future design of stamps. There were several requirements including Strong visual differences between values, fugitive inks that were resistant to washing and chemical alteration, and clearer face values.
Another design feature was the removal of the corner letters. This left more room for larger denomination values and a more ornate design. Additionally coloured paper was used for certain rates to aid identification. For example the 2 1/2d was printed on blued paper.
Printing technolgy
Bicoloured stamps need two sets of plates to print, one for the head and one for the duty or value. The plates have to be precisely aligned with the paper. occasionally errors occurred where the paper was folded over.

There could also be colour variations due to the fugitive nature of the inks used. This was deliberate to prevent forgery and washing. washing refers to the removal of the post mark. Fugitive ink changed shade when exposed to water or chemicals. it was also sensitive to light.




















































