I found this who knows how old hemp paper in an old box. You can also use paper bags from a grocery store but it has to be four ply.
Step 1: Materials Needed
You will need:
At least a yard or meter of paper
Glue strip, stitch witch or fusing tape.
A TSquare ruler
A right angle
A bone folder or creasing board
Step 2: Pattern
This is the pattern I came up with; it includes a strap and inside pocket.
Step 3: Cut It Out
Using a rotary cutter and board for the largest sections and either a scissors or Exacto knife for the fine work.
Step 4: Crease, Trim and Flatten
Crease all the edges with the bone folder and creasing board. Make sure all of the creases are sharp. Use the scissors to trim and put in any flourishes you may want. You can also use a hole punch intended for scrapbooking to make patterns in the paper. I found this small iron called a "Clover" to fuse the edges together. Glue works as well, however, fusing tape is instant. Craft glue or wood glue would be best if you wish to use glue.
Step 5: Fix the Curl
As you can see the hemp paper tends to hold its shape. It was curled up for who knows how long. I took a section and reversed it so the two coils were opposite directions from one another, when glued the two flattened each other out. This is also where I hid the magnet for the closure.
Step 6: Pencil Pocket
If you do this before putting the body together its considerably easier, the pocket not only strengthens the bottom but gives you a spot for small items.
Step 7: Strap It
Use several layers of paper to reinforce the straps and connections to the bag. You can also punch holes and sew the areas for more reinforcement.
Step 8: Waterproof Paper?
I used mink oil wax to seal and waterproof the bag. It worked remarkably well and the bag actually holds up to rain like leather now.
Step 9: Finished
The complete bag, it holds up to papers, a few books and even school work. The best part? If it gets ruined, make a new one.