A heavy-duty canvas shirt wears like iron and lasts for years, but you may feel like the tin man until you get that shirt softened up. Although the durability of canvas makes the fabric useful for tents, boat sails, backpacks, tennis shoes and artwork, the sturdy fabric also makes durable, breathable, garments. It usually takes many wearings and washings to soften a canvas shirt, but you can easily speed up the process and wear your new canvas shirt without discomfort.
Read the garment-care tag on the shirt to be sure the fabric is suitable for machine washing and drying. Although most canvas shirts are machine washable, it's important to note if the garment tolerates a warm dryer, or if it should be air-dried or dried on a low heat setting. Keep in mind that some canvas garments may shrink.
Wash the shirt in the washing machine on a warm- or cool-water setting, according to recommendations on the garment-care tag. If the shirt is soiled, use your regular liquid or powdered laundry detergent.
Mix 1 cup of baking soda with 6 cups of white vinegar to make a fabric softener.
Pour 1/2 to 1 cup of the softener solution into the washing machine during the rinse cycle. You may need to wash the shirt several consecutive times to soften the canvas.
Place the canvas shirt in the dryer with two or three clean tennis balls, and run a drying cycle on the warm setting. The balls will soften your shirt while they tumble with it. You can also use a pair of clean, white, canvas tennis shoes instead of the tennis balls. Set the dryer on air-dry if the tag indicates that the fabric shouldn't be placed in a warm dryer.
Wear the shirt. Although it may be uncomfortable at first, frequent wearings will relax the fabric as it conforms to fit your body comfortably .