I guess I can understand why ice-climbing crampons are expensive. I do trust my safety to them while climbing frozen waterfalls, after all.

However, I've never understood why crampon bags or cases need to be expensive. Thus I made my own for about $2, after a friend suggested that it's possible to make them out of old bottles.

Step 1: Materials and Tools

You will need:

- 2 old juice/milk bottles (I used the 1.89-L polyethylene kind). The higher up the bottle the handle is, the better (leaves a longer usable, 'straight' portion). Here, one bottle is intact, one already cut.

- elastic cord (ca. 4 mm diameter)- available at outdoor stores or hardware stores

- X-acto knife or scissors

- matches or lighter (optional)

- pen or marker

Step 2: Cutting Bottles and Cord

Cut the bottles as shown (around the top to remove the handle and neck), leaving all of the straight portion (or as much as you need)

Cut two lengths of elastic cord: one about 15 cm and the other about 35 cm. I singed the ends of the cord with a match to stop them from fraying (though beware noxious fumes).

Step 3: Attaching the Sections (1)

Lay the bottle sections open end to open end. Cut two parallel slots (1-2 cm) in each, and attach the two bottle sections with knotted cord, as shown. I attached the shorter cord first.

Step 4: Attaching the Sections (2)

Turn the whole thing 180 degrees and attach the bottle sections by the opposite faces, using the other cord (here, the longer cord)

Step 5: Finished Crampon Case

Standing the contraption on its end, you can put your crampons in one half (the 'bottom') and flip the 'top' over them. The halves fit snugly over the crampons, being held in place by the elastic cord.

I attached a carabiner (Note: non-load bearing, hardware store kind) to attach it to my backpack.

I estimate the whole thing cost under $2, essentially just for the elastic cord (not counting the juice in the bottles, which I would have drunk anyway)

These are optimized for my own crampons (Charlet Moser M-10's); play around and see what works best for yours.