The use of fugitive inks in the De La Rue printing of the 1964 Sabah overprints

 

The inks used by De La Rue for printing the 1964 Sabah overprinted issue and perhaps also the reprints for the original North Borneo 1961 stamps can be fugitive. It mostly involved the inks used for printing the border. In the above 20 cent example, the first stamp on the left has white margins. The second stamp also has white margins and was probably an overprint on returned Waterlow stock. The third and fourth stamps have obvious staining of the surrounding white margins with the blue ink used for the border. The fourth stamp also show partial staining of the attached selvedge above. 

Probably, a significant proportion of the inks used by De La Rue in printing this issue were fugitive. Here are some more examples where the colour inks had spread into the adjacent selvedge.