Some peculiar perforation patterns in the De La Rue 1964 Sabah overprints

 

This 5c block has only only a single perforation at the side selvedge instead of being perforated all the way to the edge. Normally De La Rue sheets were not perforated at the top and this block of 6 has 2 perforations right at the edge of the top selvedge.

This 5c block is different in having only a single perforation at the top edge of the selvedge above and also perforated through at the side. 

This 6c block shows rows of 6 perforations at the top of the selvedge which are not in line with the normal vertical lines of perforations on this block. 

This $1 block of 4 shows staining of the surrounding white paper with the yellow green ink used for printing the border. It has multiple rows of perforations at the top selvedge with half of them in line with the normal vertical lines of perforation. There is only one side perforation and this is normal for all the dollar values of this set. It is difficult to know why these extra perforations were done. Were they trials or done by mistake because they do not serve a defined purpose.

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.