There has been a lot of chatter on the Missouri Star Quilt Company Community Forum about Jelly Roll quilts. If you use one jelly roll (with 40 pieces of fabric in it), your quilt comes out to be about 55" wide by about 64" long. Since the Jelly Roll quilts are so easy to make and turn out so pretty, a lot of people have beeen wanting to make one that would fit a regular size bed. I know I did, so I figured out how to enlarge the concept to fit a twin, queen or any width bed.
First of all, you need to know how wide you want your quilt top to be. To get it to be wider than about 55", you are going to have to add jelly roll strips to your original long strip that you start with. You can add length later, but not width.
So here's how I did it:
Measure how wide you want it to end up. I made my top from the jelly rolls end up to be 72". This made the jelly roll portion cover my queen bed, and fall over the side of the mattress a couple of inches. I added an 8" border all around to make it completely cover the mattress.
So: take that number of the width of the jelly roll portion of the top and multiply by 32. You use the number 32, because that is how many rows the jelly roll quilt will have when you are finished sewing it. I got a number that was big, I think mine was around 2350". Then I measured how long each of my jelly roll strips would end up being after I sewed them with a bias seam, mine were 44" and I took off about 3" in seaming to give me approximately 41" long for each strip. Then I divided that number into the big number to get the number of strips I needed to put into my first long strip. So the math was 72 x 32 = 2350 divided by 41 = 56. I used 56 jelly rolls in my first long strip and it did indeed come out to about 72" wide.
Then I sewed some more jelly roll strips together and added them one at a time to the length of the finished jelly roll top to make it longer. I added 8 rows. I kind of overdid it on that, because by adding the border, it is longer than I normally want my quilts to be, but I guess too long is better than too short.
This one is still in the flimsy stage, I need some time to sandwich, quilt and bind. My primo Janome Horizon was in for a good cleaning this weekend, so I wanted to wait til it was back before tackling a big quilt. I plan to stitch in the ditch between the rows. Got the machine back today, will quilt on Friday.
I am excited about making more of these quilts. They are fun and fast and colorful and unpredictable as to how they will turn out. But they can be made various sizes, just be doing a little math. And when you purchase jelly rolls, you might want to get two matching ones, if you intend to make a larger top than lap size. I know they are expensive, but if you are going to make something pretty and colorful for you or a friend, just bite the bullet and go for it. Or you can use yardage and cut your own strips. I did that to add to this jelly roll, and I did it completely for my boys' alien quilt (See "A Busy Weekend" blog entry for a picture of that one.)
To use yardage: figure 1/2 yard will make 7 2-1/2" jelly roll strips, so you will need 3 yards for a regular jelly roll quilt, or more if you want to make it larger. I think you could easily use leftovers for these, they don't even have to be full strips, but then your width of the quilt might be harder to predict unless you measured your long strip as you sewed it. I don't think I would want to do that!
Good luck on your next jelly roll quilt--I have jelly rolls lined up waiting for a chance to be made into pretty colorful quilts, can't wait to do my next one!