This instructable will be following how I made version 1.0 of this bag from an old pair of jeans. It worked out OK, but the pockets aren't that useable. The cargo one pictured third is definitely an improvement on my first attempt. However both follow the same construction techniques, so this should guide you for whatever kind of chalk bag you would like to make, including a standard one without pockets.
Step 1: What You Need
Outer fabric for your chalk bag. I used an old pair of jeans for this one so I could integrate the pockets and belt loops into the design. The second one I made (see third intro image) was from an old pair of cargo pants, and I used the cargo pockets as part of the design. If you are doing a plain chalk bag, you can use whatever fabric you like, provided it is relatively sturdy.
Lining fabric: fleece or something soft works best, because it will have a stickiness factor for the chalk.
Cord/elastic: to loosen and tighten the bag
Cord stop and large eyelet for the cord/elastic
Step 2: Cut Fabric for Outer Cylinder
If you want to use more than one panel for your outer fabric that is also an option, as long as the total pieced together size is roughly 7" x 13". This is where you can get creative, so have fun!
Step 3: Cut Fabric for Inner Cylinder
Note that in this image I have the outer fabric and inner fabric folded in half on the fold - it doesn't matter whether you cut it out this way or not, but I realize this image could be slightly confusing at first glance. You want one big piece, not two small ones!
Step 4: Sew Outer Cylinder
Step 5: Cut Fabric for Bottom Pieces
Once done tracing, cut one circle pattern piece from both your inner and outer fabric.
Step 6: Sew Pieces Together
You already have your side seam sewn on the outer cylinder. Turn it back inside out, and pin circular bottom piece you just cut to the bottom of your cylinder, also wrong side out. Sew it together, removing pins as you go.
Do the same procedure for your lining fabric. Fold the rectangle in half, wrong side out (if there is a face to it). Sew the side seam. Then pin and sew the bottom circle.
In the next step you will be working with your lining inside out, which is why it is shown that way here.
Step 7: Add the Eyelet
Step 8: Add the Cord
Now for the tricky part - the cord. For a chalk bag to work properly, it needs to cinch smoothy from all sides in the lining only, which keeps your chalk safely inside when you aren't actively using it, and allows for easy access when you need some. The mechanism behind this is a double loop of the cord, which makes it cinch evenly instead of off to one side.
To keep the cord in place, you will sew a loop for it to go through on the lining, which will be on the opposite side as your eyelet. The loop should be sewn on the same distance down from the top of the bag as the eyelet, about 1.5".
Wrap the cord around the liner bag, and through the loop twice. Place the lining bag inside the outer shell, with the loop for the cord on the opposite side as the eyelet. Thread the two loose cord ends through the eyelet. See the images and diagram.
Step 9: Finish Top Edge
Almost done! The last bit of sewing is to finish the top edge. In this particular bag, my outer shell already has a finished edge as it is the waistband of pants, so I made my lining fabric a bit taller to allow me to fold it under for a clean finish.
Pin the lining under, and sew around the top of the bag.
If you choose to bind the top of your bag like the cargo one in the third main image of this instructable, take a 1.5" strip of fabric, lay it down along the outside of the bag and lining aligned to the top and, sew 1/4" from the edge. Then fold around to inside and tuck under, and sew again for a clean bound finish. Also, many commercial bags use nylon ribbon folded in half as a binding, this is an option as well.
In both bags I made, I had a belt loop integrated into the design to clip it to my harness. If you are making yours from yardage instead, you will need to add a loop on the opposite side as the cord so you can clip the bag to your harness.
Step 10: Add Cord Stop, and Finished!
Thread the two loose cord ends through the cordstop, and tie the ends of the cord so it will not un-thread.
And you're finished! Climb on!