After you stitch it out with the wss just don't rinse it out completely it will dry stiff. If you already rinsed it too much and it is very soft and you want to stiffen it just dissolve some wss in a dish with water and dip it and let dry

WSS is the Water soluble stabilizer you use when you stitch out the FSL. You use the WSS to stitch the FSL then rinse to dissolve the stabilizer & leave only the FSL design. *

I see you have your answer - so here is a *4U!

Your answer to lbrow " i have some but when i use it, it is actually 'punched out' by the embroidery...
You are using the "plastic" type of wss not the "fabric" kind.
I have included a link for the fabric type. If you live in the USA it is the best price I have found and free shipping!
On a lighter note you can still use the "plastic, saran wrap" type to dissolve to stiffen up your FSL.
Also it is a great "topper" for towels and blankets.

to know exactly what kind of stabilizer you need, go to emlibrary.com, they have a great tutorial.****

And if you rinse it too well and the design ends up floppy you can brush a coat of ModPodge sealer on both sides and it will not only be nice and stiff but you will be able to just wipe off any dust.

This also works if you mistake your other fabric stabiliser for WSS and it doesn't wash out or got stiff at all.<

>ModPodge is also great for adding glitter onto your FSL ornaments as the glitter sticks better than if you just add it to the wet design.

I've added links below to EmbroideryLibrary's Techniques page, FSL tutorials page and also where I buy all my Fabric type WSS. They have it on sale a lot and usually it is free postage in the States, most importantly it is very stable and works every time.
Hugs n roses, Meganne

you've got some great tips and answers already, so *4u and the question.

You do not mix anything with it to make it stiff. You need to sew the design directly on Ultra Solvy, which is a water soluable clear plastic like material. You then put the whole design into warm water to dissolve away the Ultra Solvy, then flatten designs between wax paper and books. There are directions on the Ultra Solvy packaging.