Painting fabric do you need FAB?

I'm missing something Jennie! Don't know what FAB is, so I need your help!

FAB is a clear blocker/primer created for use on fabric, leather, etc. I think it would be wise to use it. I painted a bench cushion and it was very stiff to the touch though I loved the new color of turquoise over and old stained brocade fabric. The FAB makes the finish more soft, so I'd recommend using it.

You don't have to use FAB, there are some other ways to do it. I've done it a few ways - chalk paint works well if it's watered down. OR use a mix of fabric softener and water on the fabric first then apply a watered down paint. This keeps the fabric soft and allows to paint to dye the fabric.

I found a video that might help...

Hi there, I've painted fabric WITHOUT FAB to some outdoor cushions (that get a lot of weather elements) and my technique has held up very well.

What is FAB. I have never heard of it. Is it like fabric medium?