There are many 3×5 notebooks to be purchased at the supply store, but they all had something wrong with them, at least for my purposes. As so often happens with things I decided to make my own.
This is all simple to do, but the resulting notebook works better for me than the ready-made ones. Note the corners are clipped slightly so it slips into a pocket easier. The string can be placed on the current working page and stuck out the bottom, so you can find your current page quickly. With the dated edges the notebooks are easily indexed when you stack them. That is handy when you have a lot of them over the years. After a notebook is full the duct tape can be removed from the plastic card and stuck to the outer layer of paper, or cut off. The plastic card may then be reused to reenforce the next notebook.