yup.. how hard? you can always paint it with paint.. or polyurethane if you need it armour hard.. but it will change the colour & hand of the fabric.. if you just need it stiff.. for your next bra, put a layer of buckram or canvas between the cup & cover fabric, or start with a molded cup bra that's firm....

If you really want to make it feel like plastic, you've got special stuff for that. My grandma uses it to make dolls, the dutch brand I've got is called 'paverpol' but there's 'pretex' and 'powertex' wich might be available outside the netherlands.

There is something called fabric stiffener, but I would test it first because it makes it pretty freakin' stiff and might be uncomfortable.

thanks y'all! I love tribe!

The fabric stiffener that Ive used is very much like white glue (Elmers), but acrylic based. I used it to stiffen crocheted baskets and boxes into something usable and it worked OK.. Also used it to refurbish a wilted western hat. It had too many summers under its brim, and needed some backbone. I dry-brushed white acrylic paint on to perk up the color from a dirty sweat stain yellow to a dazzeling white again, then after it had dried for a few days I used sev eral coats of the stiffener, and the results were good. It worked fine for a hat, but I wonder how well it will work for what you want.. Experiment. Try it and see what happens. Just dont put all your hopes in one basket, if you get what I mean. It may not work so well for stiffening a bra. good luck.

I'll have to check out the Paverpol...

I certainly hope that a person hardening fabric would have the good sense to wear something between it & their skin!

There are products that are "fabric stiffeners" (in fact, my favorite brand is actually called "Stiffy") you can find them usually with all of the glue products in JoAnn's and craft stores, it's usually used to stiffen crocheted doilies, etc. and works just fine with fabrics.