A Catalog of Philippine Papeles Sellados 1700−1899, By Douglas K. Lehmann.

Even before the 1860 introduction of revenue stamps in the Philippines, official documents had to be written on official paper. This paper had either embossments or revenue stamps printed on them. Different applications required different papers. In later years, additional stamps had to be added in addition to the already printed stamps on the paper. Douglas K. Lehman calls it Documentary Stamped Papers; they are also called Revenue Stamped Papers. An excellent 25- page catalog on these papers can be found on the International Philippine Philatelic Society website or by clicking HERE.