PP = printed pages therefore a single sided, single leaf would be 1pp. A double sided leaf would be 2pp. A booklet with 8 pages (including front and back cover on the same material) would be 8pp. A booklet with 8 pages, the inside 4 of which are on 150gsm and the outside cover on 300gsm would be 4pp + 4pp cover. A magazine therefore might be 32pp + 4pp cover. All folded and or stapled books need to have a pagination divisible by 4.