the booklet usually contains 25 leaves, separated by tissue paper and sewed on a side. This let you handle them without any risks and provides a better storage in case you may not use the whole booklet.
With the gold alloys the very thin layer of natural clay (Armenian bole) on the tissue paper prevents the leaf from adhering to the paper.
They are available in various leaf sizes; on demand the booklet may contain a different leaf number from the standard 25leaf booklet.