Page 30 - Frank Walton GB Queen Elizabeth II Wildings

1d Ultramarine

4 and 5 February 1956 - Inland printed paper rate
The minimum inland printed papers rate was increased on 1 June 1956 from 1½d for the first 2 oz to 2d for the
first 4 oz. These two window envelopes were posted in the first week of the new rate, but prepaid at the old rate.
Thus they were each charged 1d, i.e. double the ½d deficiency. The bottom cover was correctly handled with
a 1d postage due label, but the top one used a 1d Wilding as presumably a postage due label was not available.