Once you have purchased your new swag, in most cases, you will need to weather the canvas before you take it on your first camping adventure. Some swags have already been weather treated in the manufacturing process. So the choice is yours but to be on the safe side, you should weather treat the swag before you go. It will not harm the swags that have been treated at manufacture.  It will give you peace of mind!
First you need to roll your new swag out in your backyard. Be sure to cast a close eye over your new swag to check for any manufacturing faults, now is the time to find them so you can use your warranty, not once you are away camping. Once you have rolled out the swag and checked for any faults, spray your swag with a hose or use a sprinkler, don’t be shy with the water and be sure to soak the swag completely. Leave the swag to dry in a shaded part of your backyard, once it is completely dry repeat the soaking process a few more times. This process swells the fibres in the canvas, swelling around the thread of the seams making it water tight.
Be sure to leave your swag in the shade to dry out completely before you roll it back up for storage. Even though most quality swags are made with anti mildew treated canvas, storing a damp swag will certainly make it mouldy and rot the stitching.
Through the life of your swag this treatment should be repeated from time to time, especially if your swag isn’t used on a regular basis and has been stored for a period of time.
You will not have to use any waterproofing agents to water proof your new swag this will have been done by the manufacturer and will last for the life of the swag. Although at some stage you may need to re waterproof parts or the whole swag due to over scrubbing or using solvent cleaners when cleaning the swag. These waterproof agents can be purchased at any good canvas supplier. It is recommended that you use the correct products for this treatment so as not to affect the breathability of your canvas.
A good tip is to carry a wax stick in your swag; these can be purchased at most camping stores. If you find a seam that is leaking while you are away, you can just rub the wax stick on the leaking seam and the water will bead off. A common household candle will do the same job.