Not long at all. If you use their kits, they'll send you brightly colored fabrics for the top and the back, along with the pattern. They ask if you use one of their free kits you also include a quilt you've made with your own fabric.
I typically request 2-3 quilts at a time and have no problem getting them back out in 4-6 weeks (and that includes time spent making the other quilts for them with my fabrics).
I have several I've made with my own patterns and fabric, but these are the ones I've done using their fabric and patterns in just the last 3 months:
http://debzpicaday.blogspot.com/2011...75-of-365.html
http://debzpicaday.blogspot.com/2011...76-of-365.html
http://debzpicaday.blogspot.com/2011...77-of-365.html
http://debzpicaday.blogspot.com/2011...20-of-365.html
http://debzpicaday.blogspot.com/2011...21-of-365.html
http://debzpicaday.blogspot.com/2011...22-of-365.html
http://debzpicaday.blogspot.com/2011...76-of-365.html
http://debzpicaday.blogspot.com/2011...79-of-365.html
I love working with them!