Bubble wrap grades explained: bubble size, height and film

Most people order bubble wrap by asking for "the standard one". What they get is whatever the seller stocks most.

India does have a standard for it. IS 12787:1989, Polyethylene Air Bubble Film, is still listed as active on the Bureau of Indian Standards portal, reaffirmed in 2020. Its default bubble is 10 mm across, unless the buyer specifies otherwise. That last line is the important one, because it means you are allowed to specify.

Four things decide how bubble wrap performs: the diameter of the bubbles, their height, the film they are made from, and how many times you wrap the product. Small, low bubbles protect surfaces. Large, tall bubbles cushion. A barrier layer keeps the air in on long routes.

This guide takes each one in turn and ends with what to write on your purchase order.

One note before we start. We make air cushion systems and paper cushioning at our plant in Jaipur, and both compete with bubble wrap for some jobs. So read my views on where bubble wrap is the wrong choice with that in mind.

Diameter and height are two different numbers

Diameter is how wide a bubble is across. Height is how tall it stands off the flat film.

A quote may give only one of them. A "10 mm bubble" usually means the diameter. It tells you nothing about how tall the bubble is.

Height matters more for cushioning.

Think of a thin cotton gadda and a thick one on a charpai. Both cover the bed. Only the thick one stops you feeling the ropes. When a box is dropped, the bubbles squash, and a taller bubble gives the product more distance to slow down before it meets the box wall. A flat, low bubble mainly stops scratches.

Some manufacturers name their sizes by height. One large maker, Pregis, lists four cell heights on its bubble roll page: 1/8 inch (about 3 mm) very small, 3/16 inch (about 5 mm) small, 5/16 inch (about 8 mm) medium and 1/2 inch (about 13 mm) large. You do not need to buy from them to use those numbers. They give you words for a conversation with any supplier.

Small, medium or large bubbles?

Sealed Air, the company behind the Bubble Wrap brand, sorts the uses by bubble size in its Bubble Wrap brand brochure (2018):

A common set-up uses both: small bubble against a delicate surface, then large bubble outside it for the knock.

Film: layers, thickness and GSM

Bubble film is polyethylene. IS 12787 describes it as two layers of polyethylene with air bubbles trapped between them in a uniform pattern. One layer is formed into bubbles, and the other closes them.

Unless the buyer says otherwise, the standard asks for:

1. Bubble diameter of 10 mm, plus or minus 1 mm.
2. At least 7,000 bubbles per square metre.
3. A composite film thickness of at least 150 microns.
4. A yield of 100 to 185 grams per square metre.
5. Rolls 1,500 mm wide (plus or minus 20 mm) and 50 m long (plus or minus 1 m).
6. Elongation at break of at least 120%, and a minimum bursting strength for the bubbles.

The grams per square metre, the GSM, is the number I would watch most closely.

It tells you how much plastic you are getting in each square metre. For the same bubble size, a lower GSM means thinner film, and thinner film bursts more easily.

You will also be offered "3-layer" film. Sealed Air sells a triple-layer version and says it adds surface protection and resistance to tears and punctures. If a local seller offers three layers, ask what the third layer is, where it sits, and what the GSM is with and without it.

Barrier bubble: when it is worth paying for

Plain polyethylene does not hold air forever. Over a long transit time, and especially under a heavy product, bubbles lose air and height. The test method ASTM D2221 (D2221-01, reapproved 2021) exists for exactly this: it measures how much a cushion's thickness changes under a load that stays on it.

Barrier bubble adds a layer that holds the air in. Sealed Air's brochure describes its Bubble Wrap brand material as made with a "Barrier Bubble" layer that retains air. Pregis describes its Heavy Duty bubble as having a thick centre layer of co-extruded nylon for air retention, meant for heavy or fragile products with long storage and shipping cycles.

I would not pay for barrier bubble on every order. I would pay for it when the route is long or slow (sea freight, exports, stock that sits in a warehouse before it ships), or when a heavy product rests on the bubbles for days. For a light product on a short domestic route, plain bubble is usually enough. Test it before you decide.

How many wraps, and which way should the bubbles face?

UPS's own Packaging Guidelines (PDF, November 2024) say bubble sheeting is designed for lightweight items. They ask for multiple wraps and layers, with the corners and edges fully covered, and for the flat side of the film to face the product, bubbles outwards.

The number of wraps depends on the product, so I will not give you one figure. Find it with a drop test, then write it into the pack spec ("two wraps of large bubble, corners doubled") so every packer does it the same way. Our guide to choosing cushioning by product weight and fragility covers how much space to leave around the product.

When bubble wrap is the wrong choice

Bubble wrap is versatile, and I like it for many jobs. It is still the wrong answer in a few places:

1. Heavy items with sharp corners or edges. A point bursts bubbles. Use corrugated inserts, foam end caps or corner protectors.
2. Heavy items on small feet or rims. The load sits on a few bubbles, and they flatten. Spread the load with a board first, or use a firmer material.
3. Filling large empty spaces. Rolling up bubble wrap to fill a big box is an expensive way to fill air. Air pillows or crumpled paper do that job with less material.
4. Customers who want a plastic-free box. Paper wraps such as honeycomb paper do the wrapping job there.
5. Bare electronic boards. Pink anti-static bubble is made so that it does not build up a charge. But the ESD Association's guidance, based on the ANSI/ESD S541 packaging standard, says packaging used outside a static-protected area must also shield against discharge. Ask whether the material shields, or use a shielding bag first.

What to write on your purchase order

"Standard bubble wrap" is not a specification. This is:

1. Bubble diameter, in mm.
2. Bubble height, in mm.
3. Number of layers, and what each layer is.
4. GSM, with a tolerance you will accept.
5. Roll width and length.
6. Barrier layer: yes or no.
7. Anti-static: yes or no, and shielding if the product needs it.
8. Perforations for tearing, if your packers want them.
9. Roll marking. IS 12787 asks for the maker's name, roll width, roll mass, film thickness, batch number and date of manufacture on every roll. Ask for the same, so you can trace a bad roll.

If you want to keep it short, write "as per IS 12787:1989", then list only what you want changed.

Three checks you can do on a roll

You do not need a lab for these. A ruler, a kitchen scale and a marker are enough.

If I had time for only one check on a new roll, I would weigh a measured piece. It is the quickest way to see what you are really getting.

1. Count the bubbles. Draw a 10 cm by 10 cm square on the film and count the bubbles inside it. Multiply by 100 to get bubbles per square metre. At the standard's minimum of 7,000, you should count at least 70.
2. Weigh it. Cut a piece exactly 1 m long, measure its width in metres, and weigh it in grams. Divide the grams by the area. That is your GSM. Compare it with the quote and with the 100 to 185 g range in the standard.
3. Load it overnight. Put a small flat board on a single layer, stand a full water bottle on it, and leave it overnight. Compare the bubbles under the board with the ones outside it in the morning. Run the same test on a sample from another supplier, and you have a fair comparison between the two.

Also hold the film up to the light. The standard says it should be free of pinholes, tears and blisters, and that is easy to see.

If you are not sure which grade your product needs, send us a photo of the product and its weight. We will tell you honestly whether bubble wrap is the right material for it, and which grade to test.