Imperforate Stamps or Plate Proofs On Stamp Paper
30¢ imperforate partial-pair without gum The question has arisen over the years as to whether these are "imperforates for proofs on Stamp paper". They can be found as horizontal or vertical pairs, with or without gum and in two denominations, 30¢ and 50¢. It is possible they are actually colour plate proofs printed on stamp paper by the "proofer" to accompany the die proofs.
50¢ imperforate pair without gum
50¢ imperforate partial-pair with gum
Proofs on stamp paper give a more exact appearance of how the issued stamps would look than plate proofs on India paper, due to the semi-transparency of the paper. The colour of the gum, if applied, also alters the appearance of the colour of the stamp ink.
30¢ & 50¢ imperforate pairs with gum (very rare)
Varieties
30¢ & 50¢ imperforate pairs