Mailing tubes are long cardboard tubes designed for mailing large papers, such as posters or other documents, or for mailing oddly shaped items. They usually have a removable plastic cap at each end to make inserting and removing items easier. Mailing tubes are a necessity if you do a lot of mailing and shipping.
Mailing tubes come in various lengths and widths to accommodate different sized items. Most of these shipping tubes will not be longer than 48 inches (122 cm). It is important to note the usable dimensions of the tube before you purchase it -- the usable dimensions are generally a bit shorter than the actual tube, because there is some unusable space at the end of the tube.
This unusable space occurs because most of these tubes either feature snap-on plastic caps at the ends, or they fold in on themselves and snap closed to seal. Either way, you would not want your document getting crinkled and bent if it is pushed down from a plastic cap or a fold. Don't leave so much extra space that the document is continuously sliding back and forth, though -- it is best to figure out exactly how much space you need and purchase the right size accordingly.
Mailing tubes can be purchased at most post offices, shipping stores, and office supply stores. They can also be ordered online. Aside from length and width, there are other considerations to note when purchasing a shipping tube. There are different colors available that you might use for a birthday or holiday. There are also heavy duty tubes designed to withstand damage, which you might use for shipping something internationally. Telescoping tubes are also available, which are able to lengthen as needed.
Mailing tubes are best used for documents of any size that you do not want to fold, or do not want to risk being damaged if mailed in a flat envelope. A flat envelope or a bubble mailer is another option, though, if you are mailing relatively small documents. A tube might also be useful for an oddly shaped item that is too long to fit in a standard sized box.
You might also choose to fill a mailing tube with small gifts and mail it to a friend or family member for a birthday present or a care package if they are away. Most people would appreciate such a thoughtful gift. As most tubes are made of cardboard, they are easily recyclable, which is another benefit.