Colour separation proofs for each individual colour were printed for each value, and the colours combined in a process that eventually produced a full colour proof. These proofs were produced, initially, in small units, four or so and later as full sheets. This printing took place to ensure that all colours printed correctly when combined and also registered correctly. The more common sheet proofs can be easily identified from the smaller units as the latter have white borders. The stamps printed as sheets had a design that allowed for 'bleeding' between each stamp, printing over the perforations. Each value had two separate black colours, the first was applied as detail for the butterfly and the stamp value, being common for all States. and the second for the State name, Rulers portrait and/or State coat of arms, this being the 'customising' colour for the base stamps.