This is a cotton book cover. The lining is unbleached sheeting. A medium-weight interfacing is applied, giving it a moderate thickness. A fabric band of the same material is attached for adjusting the thickness. The bookmark is a satin ribbon. When open: 30cm x 16cm When closed: 12cm x 16cm However, the inner dimensions will be approximately 5mm smaller, depending on the thickness of the fabric. ★If you are purchasing multiple items, please let me know in the comments. ✳We will discount 100 yen for each additional item. For example, if you buy 3 items, you will get a 200 yen discount. If you buy 5 items, you will get a 400 yen discount. We will ship them together.