On 21 August 2006 Royal Mail introduced Pricing in Proportion (PiP), a new system of calculating postage costs which is both size and weight based.

Under this system, all post is divided into three categories 'Letter', 'Large Letter' and 'Packet'. Although Rhyme with Reason stock supplied from 21 August 2006 falls into the 'Letter' category, some products sold prior to this date may have been supplied with envelopes attracting the 'Large Letter' postage charge.

N.B. This product bears no 'Large Letter' logo. We have replaced this 'Large Letter' stock with fresh 'Letter' sized product in our retail outlets wherever possible.