This 40-sheet notebook, designed in collaboration with stationary brand Mizushima, comes in A6 Original or A5 Cousin size with a choice between plain or graph paper. Polka Dot covers contain plain paper and Striped covers contain 3.7mm graph paper, the same grid size as the Japanese A6 and A5 Hobonichi Techos. Half-circle perforations are cut down the edge of the page for the option of punching in the tab and folding it out to stick out from that page, making a convenient, built-in index. Once you no longer need an index tab for that section, simply fold the tab back into place. The notebook cover is slightly larger than the pages in order to protect the index tabs. Use these notebooks for information that can be organized into themes, such as a studying notebook or a book of recipes.