I'm going to write another post about longarm quilting on minky fabric since it can be tricky and a few tips might help. I have worked with minky quite a few times over many years and it can be a headache!
First of all, there is a big difference from one kind of minky fabric to another. You can find cheap, stretchy, minky. It will not work as a quilt backing. Do not buy it or try to use it if a customer brings you a cheap, stretchy minky. How do you know what is good quality? It should feel thick and it should have a 25% stretch or less when you pull on the stretchy side. The cheap fabric is more like swimwear and has a lot of stretch. I know from experience that it does not work to quilt with this kind as a quilt backing. It just keeps stretching and stretching and when you take the quilt off the machine, it looks like a puffy, wrinkly mess.
When loading minky on the machine, load so the stretchy part is going cross wise (horizontal). You will have much better control on how much or how little stretch you are getting when the stretch is only happening from the side clamps. If you place the stretch vertically, the rollers will be causing the minky to stretch and you may not realize how much it's stretching until you take it off and it all bunches up as it returns to it's orginal size.
I will only quilt a large overall pattern on a quilt that is backed with minky. If you try something tightly space, or try stitch in the ditch, it will shift and you most likely will end up with tucks in the minky. So I highly recommend you keep the spacing a minimum of 1" apart.
Minky is heavy so it needs a very lightweight batting. I have quilted with no batting using minky but my preference is to use a very light batting. In the quilt pictured, I used Dream Wool. It is very light and worked perfectly with this quilt. I was doing a T-Shirt quilt and if I would have used a cotton batt, it would have been too heavy. The way it was, since it was such a large quilt, the finished project weighed well over 15 pounds!
By the way, just a plug for Dream Batting. It's my favorite. I love the way their blend batt feels. They have wonderful batting in every type. My only issue is that it's on the east coast and they keep pretty much normal business hours, so if I don't remember to call them in the morning, I usually have to wait until the next day. You can purchase Dream Batting at quite a few quilt shops, but I buy it on large rolls.
After I load the minky on the machine and the batting, it's time to get the top on. I float all my tops. I do this, because I don't want any stretch on the top (not on the back either).
This quilt pictured was a challenge. It was a well-done T-Shirt quilt but it was pretty thick in places and some of the T-shirts had things you could not quilt over. I choose a large pattern and one I do a lot so I could avoid these places easily without making the pattern look like it was interrupted. This is a pattern that I can do with one hand too. When doing a T-shirt quilt, many times I have to use one hand to make sure the fabric is not stretching or running ahead of the foot. With one hand I guide the machine, and with the other I smooth the fabric as it's stitching. It takes a little practice to do this but it can be helpful with T-shirt quilts, especially when you come to an especially stretchy t-shirt.
The final picture is of the quilt off the machine. It turned out really well. And the minky on the back looks great.
