Whether you live in a warm and sunny tropical destination (lucky you!) or somewhere with more severe seasons, chances are that the onset of spring means an increase in precipitation. As crafters of garments and other products that may need to endure the outdoors, waterproofing is a simple and inexpensive precautionary step you can take to keep your work looking fabulous all year round!
Some fabrics typically used for outer garments are naturally more water repellant, and can be fairly effective even without waterproofing treatment. Wool, for example, has a unique fiber structure that can both repel water and be incredibly absorbent based on the way it’s treated. If felted or treated with lanolin, wool can be fairly waterproof and even antibiotic.
Other woven fabrics that are primarily made from synthetic fibers, especially those like polyester, also tend to be less naturally absorbent. Don’t let this discourage you from using your dream fabric, though. Look and feel don’t have to take a back seat to functionality. For natural fiber fabrics that take on water more easily, there are some cheap, simple to use, and effective products on the market for waterproofing fabric that will take your outdoor garment game to the next level.
The most popular is a waterproofing spray. There are many brands of these, so shop around and read reviews before picking your poison. These sprays are applied directly to the finished garment, or to the fabric before you use it. Most sprays apply a thin polyurethane or other chemical coating to the material, so tread lightly with your extremely delicate fabrics. The upside to waterproofing spray, also, is that it is least likely to affect the color or appearance of the fabric, and frequently preserves some amount of breathability.
If you’re looking for a natural DIY method for waterproofing fabric, you have more options! One is pretreating your fabric by soaking it in a laundry detergent mixture, followed by an alum powder mixture. Hardier fabrics can be treated with turpentine and soybean oil, wax, or linseed oil as well. It is important to keep in mind that solutions like this can affect coloration, frequently turning the fabric a shade darker.
One crafter I met swears by treating her clothing fabrics with a mixture of mineral spirits and clear silicone caulking.
As you can tell, the marketplace will not leave you empty handed in your attempt to waterproof fabrics. Whichever method you choose, always be sure to test a small area before you treat the whole garment, start with a clean fabric, and be sure you are treating the right side of the fabric. Many of these treatments are flammable (before they dry), so maybe forego the candle-lit mood lighting. Also, don't forget to sew a label to your clothing.