FAQ: Poly Mailers

Poly mailers are an economical, yet effective way to ship a wide range of products.  Below are common questions and answers about poly mailers.

What are poly mailers?

Poly mailers are lightweight, yet durable, plastic bags used to ship products.   Poly mailers have a self-sealing closure eliminating the need for tape.  Shipping labels or writing can be directly applied to the exterior of poly mailers for shipping purposes.  

What are poly mailers made from?

Poly mailers are made from polyethylene film.  This material is made from blends of plastic resin which is melted down and blown into an extruded film.  The polyethylene film is then converted into mailers.  

What are the benefits of poly mailers?

  • Waterproof
  • Puncture and tear resistant
  • Secure adhesive closure
  • Provide confidential shipping
  • Cost effective
  • Lightweight
  • Compact storage
  • Efficient to use

Why should you consider using poly mailers?

While boxes are necessary for shipping many items, they are not necessary for shipping all items.  Shipping with poly mailers will result in significantly lower shipping costs.  This is because the mailers are light weight and smaller in size.  Shipping carriers use dimensional weight to determine charges for shipping.  Because poly mailers take up less space, they result in a lower dimensional weight value, resulting in lower shipping charges.   

What industries use poly mailers?

Poly mailers are most commonly used by eCommerce businesses, retailers, medical and pharmaceutical companies.  

When should I avoid using poly mailers?

Although poly mailers are versatile, there are some situations when poly mailers are not ideal:

  • Shipping fragile items
  • Shipping multiple products at the same time
  • Product is too large

What is the best way to ship poly mailers?

Poly mailers can be shipped via USPS or any other parcel shipping service, such as UPS, FedEx or DHL.  Shipping rates will vary depending on the carrier, the distance to ship the product and the shipping service selected.  

Are poly mailers considered envelopes?

Poly mailers are considered non-paper envelopes.  This means that they are non-machinable and not able to be sorted using automated equipment, and therefore subject to additional charges.  

Can you ship poly mailers via USPS?

Yes, poly mailers can be shipped with the US Postal Service.  Poly mailers can be shipped using USPS First Class, Priority Mail or Media Mail services.  

  • First Class – This applies when shipping a package weighing 13 oz. or less.  It is the cheapest way to ship items and is best for lightweight items.
  • Priority Mail – This service can be used to ship packages weighing up to 70 lbs.  This service will typically deliver packages in 1-3 business days.  Shipping charges are calculated based on the distance from ship point to the destination.
  • Media Mail – A cost effective service used to ship boos, CDs, DVDs and other print materials.   

What are USPS rules and guidelines for poly mailers?

  • Poly mailers must be at least 2 mils thick for shipments up to 5 lbs. and at least 3 mils thick for shipments up to 10 lbs.  
  • The overhang of the poly mailers should not exceed ½” when the package is laying flat.
  • First Class Mail can be used for a poly mailer weighing less than 16 oz.
  • Priority Mail can be used for any poly mailer weighing under 70 lbs.
  • USPS Media mail can be used for any poly mailer weighing under 70 lbs. with contents including books, DVDs, vinyl records, sound recordings and printed music.  

Are poly mailers recyclable?

Poly mailers can be recycled.  They often contain some level of post-consumer or post-industrial material.   

What types of products are ideal to ship in poly mailers?

Poly mailers are excellent for shipping soft goods, such as clothing, apparel, bedding, blankets, towels, fabrics, footwear, accessories and non-perishable items.  

How to choose the right size poly mailer?

  • Measure your items – Fold items and arrange in a manner consistent with how they will be shipped.  Use a tape measure or ruler to determine the length, width and height of the item/s.   Take note of your measurements.
  • Use formulas to determine minimum required mailer dimensions:
    • Minimum Width = Item Width + Item Depth + 1”
    • Minimum Length = Item Length + Item Depth + 2”
  • Consider fabrics – Different fabrics have different thicknesses which will impact the packaging.   A long sleeve cotton t-shirt, although the same shape as a knitted wool jumper, only takes up half the space.   The same goes for jeans vs. leggings, sheer stockings vs. fleece stockings, etc.
  • If you’re still unsure after measuring and considering the thickness of your items, go up one size level to be safe.

What is the best size poly mailer for clothing?

These sizes below are most commonly used for shipping clothing and apparel accessories.  

  • 9 x 12” (P511):   T- shirts, thin shirts, light undergarments, pajama shorts, mini skirts and children’s size clothing.
  • 10 x 13” (P512):   Versatile size ideal for blouses, dress shirts, shorts, skirts and more.  Depending on the thickness of the fabric and how the items are folded, up to five large shirts could fit comfortably.  
  • 12 x 15 ½” (P513):  Perfect for thicker and/or longer clothing items, such as sweaters, jeans, dresses, sweatshirts and hoodies, typically up to size large.  
  • 14 ½ x 19” (P514):  Suitable for all types of clothing, including shirts, dresses, pants, coats, vests and more.   This size is also recommended for larger sizes such as XL and XXL.  This size is also recommended for blankets and bedding items.    

Can I put a stamp on a poly mailer?

Yes, you can use stamps to ship poly mailers.  The amount of stamp postage required to ship the mailer will depend on the size and weight of the filled mailer.  

Where can I buy poly mailers?

SupplyLand features a range of stock poly mailers.  SupplyLand poly mailers feature a proprietary 3mil film which is up to 20% thicker than the industry standard.  Shop Now.

The information contained in this article is for informational, educations and promotional purposes only and is based on information available as of the initial date of publication.  It is the reader’s responsibility to ensure compliance with all applicable laws, rules, codes and regulations.  If there is any question or doubt in regard to any element contained in this article, please consult a licensed professional.  Under no circumstances will SupplyLand be liable for any loss or damage caused by your reliance on this article.