I have discussed Plarn before, but in case you missed it, Plarn = PLastic yARN. It is made from grocery and produce bags.
Plarn Plus is when you twist other materials with the plarn as you are working. To the Left is a close-up of what it can look like. In this case, it's strands of black and white scrap yarn twisted with plarn that is white with black lettering.
Pros and cons to Plarn Plus:
*By adding recycled or scrap yarn, you keep it from looking so plastic-y, and have many more options with colors,
*While the plarn itself is pretty spongy, adding yarn also adds a softness,
*Adding yarn adds additional strength
*While is still can be rinsed and air dried, it takes more time,
*Yarn does add more weight, so it is heavier when empty,
So, do the pros outweight the cons? It all depends on what you want to use it for. As a general purpose bag, Plarn Plus works better. But for groceries, where you want to insure that it is clean, regular plarn may be the better option.
(This black and white Plarn Plus Tote is currently available at our Etsy store. Comet ake a look. http://www.fullhousecrafts.etsy.com)