How to Make a Cardboard Shipping Container
If you have an item to ship that is not a standard size, you can make your own shipping container easily. Here is what you will need: corrugated cardboard sheet (large enough for your container), packing tape, metal ruler/straight edge, razor knife, cutting board, marker, tape measure, paper, pencil.
Step 1: Measure the item you want to ship and record the measurements on a piece of paper. Determine your shipping container dimensions based on the size of your item plus any allowance for packing material that may be used to protect your item from damage.
Step 2: Make a drawing of the flat container using the dimensions of the item and surrounding packing material from step 1. You have to use your imagination a bit to visualize how the box will need to be folded to make your container. I try to minimize joints that need to be taped, so I chose a simple layout with the least seams. You'll need to think about how folds will occur and how flaps might overlap to create the container. Don't worry - you've got this - you can do it.
Step 3: Using your marker (I use a Sharpie) transfer measurements from your drawing to the cardboard sheet. I usually begin with the perimeter dimension and lay that in first to show my overall size. Then I draw in the rest of the lines using my marker so I can easily see the lines.
Step 4: Use your straight edge and your razor knife to cut out the cardboard. I use a cutting board or mat below the cardboard so that I don't damage my flooring. I usually begin by cutting the perimeter out first. Now I can better see what lines need to be cut and which just need to be scored for folding. If you are confused, just write cut or score on each line. The writing will be on the inside of the container, so no one will know! To score a line for folding barely insert the knife blade into the cardboard, just enough to cut through the surface layer. Be careful not to cut all the way through the cardboard.
Step 5: Fold the container into it's final shape and tape the joints with the packing tape. Be sure to leave the one side open to insert your item. Place the item inside, with the required packing material and test the fit. If the fit isn't just right you can make adjustments as needed.
Now you're all done!