Many of our customers will be confused about the various options when ordering custom paper packaging bags for their business for the first time. Especially about the paper bag weight option, different bag types’ basis weight looks similar, and they think that is impossible. Actually, this number is not referred a single bag weighs but a specification of the paper it is made from.
In industrial manufacture, the material paper is usually be put n storage in two styles: paper roll and paper sheet. The paper roll is wrapped from a long paper; it’s large and has a core, weights per roll are calculated in tons. Paper roll is the most used material in printing and paper bag producing factories because of the high efficiency. And the specification is typically stated by lbs and gsm, as we see on the product catalog.
Lbs is the plural form of lb. It states how many pounds a ream (500 sheets) of the particular size paper weights. Europe and Us merchants love to use lbs to describe the paper weight and match with inch as the length unit. However, not all the paper sheet types in the same size and density. So most of the time, even though two different papers have the same lbs, they weigh different in the same size.
Gsm is an abbreviation for the “grams per square meter,” also called g/m2. Gram and square meter are the universal measurement unit worldwide and more popular in international trade. One thing worth knowing is that lbs and gsm can not be transformed by a formula simply; different paper types will come with different results. You can ask our professional team for a correct answer.
The basis weight is an important option when customizing a paper bag; it influences many factors.
We may have a misunderstanding that the heavier the basis weight, the thicker the paper. It indeed is most of the time, but the direct factor that influences the paper thickness is density. We can understand it as the heavier the basis weight and the thinner the paper, the higher its density. That means it will get better tear-resistance performance, load much weight, and is not easy to break during carrying.
Likewise, the basis weight of paper also influences its stiffness. Take the SOS bag, which is usually seen in the groceries, as an example. It has a flat bottom, can stand up without help. But suppose it has a lighter basis weight. In that case, the opening will be incurved because of the weaker stiffness, not so convenient when loading goods. In comparison, a paper bag with heavier basic weight, its wall will be more straight, and the opening will keep the same size as the bottom after unfolding.
The higher the stiffness of paper, the more flatness of the surface, and no wrinkle influence the effect during printing. And during the actual use procedure, the bags are also kept flat and let your brand promotion design looks more awesome rather than rumpled.
So is that the heavier the basis weight, the better showing effect? That may not be. Take the paper shopping bags as an example. They are made from kraft paper with heavier basis weight and typically have been film-coated. If you choose an over heavier basis weight option(>250), the folded rims may break because of the over-high density and influence the appearance and durability.
Except for the quality, the cost is the most factor that our customers care about. Typically, in two identical types of papers, the one with heavier basis weight will cost higher. And due to the increased thickness, it needs more cartons for packaging. Under a large bulk-purchasing situation, the shipping cost also increases. Especially the shipping cost is crazy now, and this factor becomes more and more important; sometimes, the shipping cost is even higher than the cost of the products.
Most of the SOS kraft paper bags for groceries use are purchased from the local wholesalers. They have no logo and design printed. The bag is without handles and needs to hold the bottom when carrying or pinch the top, so it has a lesser requirement to the weight capacity. These kraft paper bags’ basis weight is typically at 30-60gsm. Some large-size ones are made from 80gsm paper for bearing heavier goods. And some food-grade paper bags for deli packaging, their basic weight is typically at 20-30gsm.
The paper shopping bags get a higher weight-carrying requirement, and the handles make the stressed area more focused. So they are made from kraft paper or coated paper with heavier basis weight, typically at 80-230gsm. A heavier paper also makes a better appearance and helps the brand promotion.