How to tell the quality difference of paper bags?

Telling the quality difference of paper bags, we need to use hands to touch and feel.

1. Paper quality. 

White card paper and art paper are most popular for making bags. The advantage of white card paper bags stands very well(shape good), The advantage of art paper bags is paper more whiter and the printing effect good(vivid printing colors).  White card paper is tough and hard touch,but the art paper is very soft.

Thickness for white card paper: 190gsm and 210gsm(grams per square meter) etc

Thickness for art paper,128gsm,157gsm,180gsm,200gsm,230gsm,300gsm etc

More thickness,of course quality is much more better.  

Both of this 2 kind of paper bags need to be matte or glossy laminated. For kraft paper,no matter it is white kraft or brown kraft,no need to be laminated(paper bags for carrying flowers inside needs to be laminated).

2. Shape is good,surface is clean,no glue out,putting a brisk weighted 5KGS inside the bag to inspect the weight bearing ability.