A dieline serves as a package template that ensures proper layout for a printed product. It is a diagram that shows all the cut lines and folds of a package in flattened form. They are also used for envelopes, pocket folders and more. There are a few steps toward creating proper, accurate die lines for items such as boxes.
Sometimes a client will send a printing company an example of how they would like their packaging to look. In this case, you will want to take the package they send apart to see where tucks or graphics are, also being sure to take measurements. If you simply have the product with no package reference, you will need to make measurements of the product itself, using wrapped paper to estimate the needed size.
From here, die lines are then created in Adobe Illustrator with certain design standards. You can then use a hard copy of the die line you create to test with the product you are packaging. Once you have it right, hard copy prototypes are made with heavyweight paper or other materials. Following careful checking of prototypes for sturdiness and other factors, the finished packaging product will be ready to hit the shelves.