The most lightest backpack in the Fredrik Packers range is the obviously named Light Weight Back Pack series. Three sizes are available in large, medium and small, which is suitable for daily use or for professional use by messengers. One reason for its lightness is the stripping of inner linings, thus making this bag resistant to water. Couple that with comfortably padded shoulder pads, this all rounder is great on the bicycle as well as off the bicycle. They have come up with a new colorway in purple and blue scheme as reported here but there are plenty of other colorways to choose from on their website.