The proposal for a uniform rate was the outstanding feature of the plan, but there were others of importance. It was a chief merit that the plan might be introduced without causing any serious diminution of net revenue, and the object of the further proposals was so to modify and simplify the working methods of the service as to enable the increased traffic which a low uniform rate would inevitably bring into the post to be dealt with without a proportionate increase in working expenses. A vast increase in the number of letters must occur if the revenue was to be maintained, and this increase was confidently anticipated. With the existing rates there was a very large clandestine traffic in letters outside the Post Office, and it was calculated that a low uniform rate would effect the complete suppression of that traffic, and attract all letters into the post. But in order to maintain the net revenue, it was essential to simplify effectively the methods of working. This simplification was to be secured by the introduction of the system of prepayment, and the principle of charging by weight. Covers and sheets of paper bearing the revenue stamp already impressed were to be sold at all post offices. The postage label, which has become so characteristic a feature of post office business throughout the civilized world, was proposed as an expedient to meet a certain exceptional case. If any person bringing a letter to the post should not be able to write the address on the stamped cover in which the letter was to be enclosed, Sir Rowland Hill suggested that "this difficulty might be obviated by using a bit of paper just large enough to bear the stamp, and covered at the back with a glutinous wash, which the bringer might, by applying a little moisture, attach to the back of the letter, so as to avoid the necessity for redirecting it."[76] Letters prepaid in either of these ways were to pass through the post as franks,[77] i.e. without change or record. By this method a great reduction in the work of the Post Office would be effected. Under the existing system it was necessary to record and charge forward on the postmasters all letters the postage of which was to be collected on delivery, and these letters formed the vast majority. All such labour would be dispensed with. The increase of the number of letters was to be further encouraged by the provision of additional facilities, such as the establishment of day mails and increased frequency of deliveries in towns.[78]