This private mail sack was for staff personal mail such as letters with stamps on and freepost items. It was given directly to Royal Mail with no processing by the Post Room. To the left is the large pair of scales used for weighing heavy mailbags. To the right are the other mailbags for large letters, first and second class, and for ‘PPI’ (printed postage impression), mail that was paid at an agreed bulk price rather than per item. This was mainly Jiffy bags containing small map despatch orders and CD/DVD media. OS developed a sustainable cardboard case for the latter.