Choosing the correct poly bag size affects customer satisfaction, shipping costs, and packaging efficiency. A bag that is too large wastes material and may incur higher dimensional weight fees. Conversely, an undersized bag risks tearing, product damage, and a poor customer experience. Standardizing packaging ensures professional presentation and protects garments during shipping. Selection begins with a precise measurement of the product itself.
The Core Calculation: How to Determine Bag Size
Determining the appropriate poly bag size translates the three-dimensional measurement of a folded garment into the two-dimensional requirements of a flat bag. Start by adopting a consistent retail folding method, then measure the folded item’s width, length, and depth (thickness).
The required bag width is calculated by adding the folded item’s width and depth, plus an allowance of one to two inches for comfortable insertion. This allowance ensures the bag wraps around the item’s thickness without strain. For the bag length, add the folded item’s length to the self-sealing flap or lip, plus one inch for seam allowance and easy closure. Ignoring depth, especially for bulky items, causes the seals to stress or fail.
This methodology prevents overstuffing and material tearing. For example, a sweatshirt folded to 10 inches wide and 2 inches thick requires a bag width of at least 13 inches (10 in. width + 2 in. depth + 1 in. allowance). The final bag dimensions must accommodate this calculated width and length to maintain a neat, professional appearance.
Standard Size Recommendations for Different Shirt Types
Standard T-Shirts (S-XL)
For standard adult t-shirts (S-XL), the most common poly bag dimensions are 10 inches by 13 inches or 11 inches by 14 inches. These sizes accommodate a single, neatly folded shirt while minimizing excess material. The 10×13 inch bag is the industry standard, working well for lightweight cotton or jersey t-shirts folded to approximately 9 by 11 inches. Using a size in this range streamlines inventory management, covering the majority of t-shirt orders.
Long-Sleeve Shirts and Hoodies
Thicker or longer garments, such as heavy long-sleeve shirts, sweaters, and standard hoodies, require a larger bag to account for increased material volume. A 12-inch by 15.5-inch bag is generally suitable for a single folded hoodie up to size large or a heavy knitted sweater. Hoodies demand a larger size because the hood and pocket material significantly increase the item’s overall depth. For extra-large hoodies or packaging two medium-weight sweaters together, a size like 14.5 inches by 19 inches or 19 inches by 24 inches is necessary to prevent excessive compression and wrinkling.
Folded Dress Shirts and Bulk Items
Items folded with cardboard inserts, such as formal dress shirts or polo shirts, maintain a uniform, flat profile. A 9-inch by 12-inch bag is practical for a single dress shirt or light blouse, providing a tailored fit that prevents shifting. When packaging multiple items, such as two t-shirts or a dress shirt with an accessory, the 10×13 inch size offers a comfortable margin. For bulk orders or items with high depth, like a stack of five t-shirts, consider using a gusseted poly bag. Gusseted bags feature a fold on the side or bottom to provide extra expansion and volume capacity beyond standard flat dimensions.
Essential Features of Poly Bags
Material Thickness (Mil)
The durability of a poly bag is quantified by its material thickness, measured in “mil,” representing one-thousandth of an inch. For apparel packaging, the appropriate thickness balances protection, weight, and cost. Lightweight clothing items are safe in bags 1 to 2 mils thick, with 2 mil being the most commonly used and versatile option. Bags in the 1.5 mil range provide sufficient protection against dust, moisture, and handling without adding unnecessary weight to the shipment. Thicker bags (3 mil or more) are usually reserved for items with sharp edges or heavy industrial components, which are not typically required for soft apparel.
Self-Sealing Lip and Adhesive Quality
A self-sealing lip simplifies the packaging process and ensures a secure closure for storage and shipping. These bags feature an adhesive strip on a flap that seals to the main body of the bag. The adhesive quality is important, as it must maintain seal integrity through temperature and pressure changes during transit. A strong, tamper-evident adhesive strip provides customers confidence that the package has not been opened since it was sealed.
Air Release Holes (Vents)
Air release holes, or vents, are small perforations placed in the poly bag to allow trapped air to escape quickly when the bag is sealed and compressed. This venting process is important for two reasons. First, it significantly reduces the package volume, allowing for tighter stacking and storage. Second, vents prevent the bag from inflating or bursting when exposed to altitude changes during air freight. These small holes are usually positioned beneath the seal and release air while still protecting the garment from outside dust and debris.
Packaging Best Practices and Efficiency
After selecting the properly sized bag, focus on optimizing the packing process for presentation and logistics. When inserting a garment, press firmly on the package to expel all trapped air through the vents before sealing the adhesive lip. This ensures the package is flat and compact, which helps minimize dimensional weight charges. Achieving a tight, air-free seal creates a professional look and reduces item movement inside the mailer.
Employing a consistent folding technique ensures the garment fits neatly within the chosen bag dimensions, preventing wasted space or wrinkling upon arrival. Sellers often include a branded postcard or thank-you note inside the bag, which elevates perceived value and helps stabilize the folded garment. For maximum logistical efficiency and cost control, limit packaging inventory to only two or three standard poly bag sizes. A seller can typically cover most of their product line using a standard t-shirt size (e.g., 10×13) and a larger hoodie/bulk size (e.g., 14.5×19), simplifying ordering, storage, and fulfillment.