Home Uncategorized How to make a stiff t-shirt look and feel vintage – will shrink, so buy large: Wash 3-5 times in hot water with 1/4 c sodium carbonate washing soda 2 c salt (use smaller batch after first wash do not added directly onto shirt). Dry on high heat after each wash. Using fine-grit sandpaper, lightly swipe over logo in circular but irregular strokes.