I bought 1.5 meters of black "quilted" fabric. Black, only because the other color choice I had was a dark brown. I then bought 4 meters of webbing that I was going to cover with funky fabric (which I didn't in the end), a 24" zipper (because a sleeping bag zipper was really, really long...and this was my first zipper. I just threw it together -- so I don't have a lot of great details for you, but, if you imagine it in your head, you can do anything! good luck and don't hesitate to ask me questions if you have any. Remember...this blog is for my kids, and not meant as a professional blog for quilters. It's my take on doing things my "Margo/Mom" way -- so forgive me if it doesn't make sense to you!
On with the photo's!
First step is to lay out your fabric and trim so it's big enough for your cutting board. You can see that I have added an envelope to fit my rulers. The next step is to bind the whole piece like a quilt. you then add your envelope and sew down the two sides and the bottom of the sleeve (the bottom is positioned to the bottom of your whole case -- so when you fold it up, it will be supported as well by the bottom.
The next step is to add your zipper to one side. it starts at the bottom of your sleeve to the top of your cover. You have a zipper only one one side. I found it was enough because I only need enough room from the top and sides to slide in the rulers into the sleeve and extension table and cutting board into the main part of your carrier.
Your handles are the last task for your carrier. Sew along both sides. I placed one handle first, then measured how much so it was equally placed on the opposite side. Remember to reinforce/sew the tops of the handles where they join the main part of the bag so the handles do not rip from the bag when you are carrying them.
The only changes that I would make, would be to add a button closure, or even an extra zipper along the top so when it is carried it doesn't gape. (you could use a longer zipper so it would go along one full side and along the top to close it shut--or maybe velcro).
What I have works and I love it! It may not be fantastically fancy, but it protected what I had to get to retreat in one piece!