Anyone living in Posadas could tell where this bag's name comes from, mainly because of the distinctive colors. I made it for myself more than a year ago, but ended up giving it to a dear friend from college, Rosalba.
The yarn, obviously, comes from recycled market bags, but don't be fooled. I'm into recycling, of course, yet, this project has more to do with the fact that I´m kind of a cheap hooker who can't afford to buy fancy yarn for fancy projects.
I featured this pattern in Spanish on http://curupisa.blogspot.com.

Yarn made from recycled plastic bags.
Use two skeins: a big one with mixed colours, made out from bags with writings (colour A) and a smaller one (colour B) made from plain colour bags (to tell you the truth, I didn’t pay attention to the amount of bags I used).
I used a 6mm hook (USA J/10, UK 4)

18''(45 cm) high.
16'' (40 cm) wide at the top.

10 sc and 10 rows= about 4''/10 cm.

You can find great tutorials anywhere on how to make yarn from plastic bags.

Starting with skein A, make a circle of 5 ch.
1st. round: 1 ch and 10 sc. Close this and all rounds with a sl st.
2nd rnd: 1 ch. and 2 sc on each sc. Close.
3rd. rnd: 1 ch., *1 sc over first sc, 2 sc on next one*. Repeat * across round.
4th. rnd: 1 ch, *1 sc over first 2 sc, 2 sc on next one*. Repeat * across round.
5th.rnd: 1 ch, *1 sc on next 3 sc, 2 sc on next one*. Repeat * across round.
6th.rnd: 1 ch, *1 sc over next 4 sc, 2 sc on next one*. Repeat * across round.
7th. rnd: 1 ch, *1 sc over next 5 sc, 2 sc on next one*. Repeat * across round.
8th. and 9th rnd: 1 ch, *1 sc over next 6 sc, 2 sc on next one*. Repeat * across round.
10th. 13th. rnd: sc on each st.
14th. rnd: 1 ch, *1 sc, 1 ch, skip 1 sc*, repeat.
15th. to 17th rnd: 1 ch, *1 sc on each ch, 1 ch, skip each sc*, repeat.
18th. to 19th. rnd: use skein B. 1 ch, *1 sc on each ch, 1 sc on each sc*, repeat.
20th. to 30th. rnd: with skein A, like rounds 14 and 15.
31st. to 32nd. rnd: like rounds 18 and 19, using colour B.
33rd. to 36th. rnd: with skein A, like rounds 14 and 15 c.
34th rnd: 1 ch., 1 sc on each st.
35th rnd: 1 ch, *1 sc on the next 22 st, 20 ch, skip next 16 sc*, repeat once.
36th and 37th rnd: 1 ch, 1 sc on each st across to the end.
Fasten off. Weave in end.