Keeping track of your collection is an important task in your collection. As the collection grows, you should keep track of the pieces you purchase. The information recorded can be used for future references for many reasons. Sometimes it's important information to know and sometimes it's just fun to remember. Also tracking what you have helps to fulfill a "set" or series within your collection. For instance it's good to know if you need one or two specific planes to complete a set of a particular type or style. There's certainly nothing wrong with having a few duplicates in your collection (some collectors strive for it), but purchasing something extra should be an informed decision and not something that happens accidentally. Otherwise, you're wasting money that could be spent on an entirely new item. Having to many of one particular size and type can quickly get out of hand. There are some planes that are just a lot more abundant than others and knowing what you have and what you need is important. A suggestion would be to break the workbook up into sections, based on what you collect. For instance you may break up smoothers, jacks, fore and jointers in separate sections so things are easier to track. You can also use a particular catalog or catalog reprint as a reference to collect a catalog or manufactures set of planes. Under "Contents of Planes added Page #" would be The Name of the plane and model number, then the page it is listed on. If you have more than one of the same kind, only one instance would need to be listed here as long as they are on the same page. Then on the actual page the plane is listed and described for collection and inventory purposes. Knowing What You Need. On top of making sure you don't accidentally re-purchase an item, having an accurate account of your collection can assist in figuring out what you need/want to add to it. Regardless of what you collect, there's undoubtedly something you're on the hunt for. You may remember one or two of the "big" things you want, but there's probably a longer list of smaller items that easily slip your mind. Knowing what's already in your collection will help remind you of what you don't have. Say you're creating a list of items that are a part of a smaller series within your collection (i.e., a specific author within a book collection). By looking at what you have, anything you're lacking will stand out. This will make it easier to create a separate and more accurate wish list. Jotting down a list of things to look out for is great, but without knowing what you already have, it's easy to leave something off your list.