Roll of clear small-bubble cushioning wrap used for void fill and protection

Void Fill and Protective Packaging: Choosing Between Bubble, Foam, Paper and Honeycomb

Damage in transit gets solved by adding material. More bubble, thicker foam, more loose fill. It usually works, and it is usually the most expensive way to work, because the dunnage that stops the damage also adds cube, and cube is billed on every shipment you make from then on.

The cheaper fix is picking the right material for the failure you actually have. Most of these decisions go wrong at the first step, because three different jobs get treated as one.

Three jobs that get conflated

Cushioning absorbs shock. It decelerates the product over a distance when the package is dropped. It only works if the material compresses under the load and then recovers. This is what protects a fragile item from a drop.

Blocking and bracing stops the product from moving inside the box. It does not need to compress — it needs to be rigid. This is what keeps a heavy item from sliding into the wall of a carton and punching through it.

Void fill occupies empty space so the contents do not shift and the box does not collapse when something is stacked on it. It is the least demanding of the three and the one people over-buy for.

The mistake: asking one of them to do another's job. Loose fill poured around a 40 lb machined part is void fill being asked to block — the part settles into the bottom corner in the first hour of transit. Rigid honeycomb packed tight against a delicate instrument is blocking being asked to cushion — there is nothing left to absorb the drop. Decide which of the three you need before you pick a material, and accept that a lot of packs need two of them.

Bubble: pick the cell size first

Bubble is a cushioning and surface-protection material. Air trapped in a formed cell compresses on impact. Cell height sets how much drop energy it can absorb, and it is the first thing to specify.

Cell size Use it for Where it fails
3/16" Surface protection and interleaving. Wrapping glass, finished panels, small parts, electronics. Conforms tightly, layers well, takes the least cube. Almost no drop protection on anything with mass. It stops scratches, not impacts.
5/16" The general-purpose cushion. Moderate-weight items, multi-layer wrapping, filling small and medium voids. Dense items bottom it out in one drop. The cell collapses and the product hits the box.
1/2" Large and heavy items, large voids, furniture, appliances, anything with real drop exposure. Cube. It is mostly air in your warehouse and mostly air in the carton, and it will push a parcel into a higher billable weight faster than anything else on this page.

Wrap in layers, not once. A single wrap of 1/2" gives you one cell height of travel. Two or three wraps of 5/16" give you more usable deceleration distance and conform better around corners and protrusions. On fragile items the number of layers usually matters more than the cell size you started with.

Bubbles in or out. Bubbles face the product when you want cushioning, because the cells have to deflect against it. Bubbles face out when you are protecting a soft or high-gloss finish, so the flat film sits against the product and the cells do not emboss it. On lacquered, plated and piano-gloss surfaces, bubble marking is a genuine defect — use a foam wrap or an interleaf sheet instead of arguing about orientation.

Perforated or not. Perforated rolls tear to a fixed length by hand and take real time out of a repetitive pack. They also waste material whenever your item does not divide evenly into the perf length. If you wrap one size all day, perf to that size. If your mix is varied, buy unperforated and cut.

Cohesive and cling grades stick to themselves and eliminate tape on the wrap. They cost more per foot and save tape and labor. At volume it is worth pricing both ways with your actual pack times rather than guessing.

The bubble wrap request-a-quote page takes cell size, width, roll length, and whether you need perforation, cling or anti-static.

Foam: density is the spec, thickness is the adjustment

Foam is where most cushioning money gets wasted, because people buy it by thickness and thickness is the second variable, not the first.

A foam cushion works by deflecting under the product's weight and decelerating it over that deflection. How much it deflects depends on static loading — the product weight divided by the bearing area of foam under it, in pounds per square inch — measured against that foam's density.

That leads somewhere counterintuitive: too much foam is as bad as too little. Set a light item on a large area of dense foam and the foam barely deflects. It behaves like a board and transmits the shock straight through. Set a heavy item on a small area of soft foam and the foam bottoms out, and once it bottoms out the product is hitting the carton floor. Either way the contents break and the packaging comes out looking fine, which is why this failure gets diagnosed as "not enough foam" and made worse.

Density, in pounds per cubic foot, sets the range of static loading a foam works across. Low-density foam deflects easily and suits light items. High-density foam needs real weight on it before it does anything, and suits heavy ones. Thickness then sets how far the product can travel while decelerating — that is what you increase when the drop height goes up, not when the product gets heavier.

The practical version: for your product weight and bearing area, work out the static loading, pick the density whose cushion curve is lowest at that loading, then pick the thickness that gets transmitted G below what the product survives. Foam manufacturers publish cushion curves for exactly this purpose. Ask for them. A supplier who cannot produce a cushion curve for the foam they are quoting is selling you a thickness, not a cushion.

Open cell vs. closed cell

Polyurethane, open cell, is soft and light, compresses easily and recovers slowly. Good for light, delicate and irregular items, for surface protection, and for fabricated inserts where appearance matters. It absorbs water and it is a poor choice for anything that gets wet or that takes repeated high-energy impacts.

Polyethylene, closed cell, is firmer and resilient, does not absorb water, and survives repeated impacts — which is why returnable and multi-trip packaging is built from it. It comes in roll, sheet and plank, and it is what most fabricated cushion sets are cut from. Cross-linked polyethylene is finer-celled, cuts cleaner and looks better, and costs more; use it where the customer sees the foam.

Pouches are the ready-made version. A foam pouch wraps and cushions a small part in one motion with no cutting and no tape. Material cost per unit is higher than cut roll stock and labor cost per unit is lower, so which one wins depends on what your pack station costs per hour. Time both on your own bench before deciding — it is a ten-minute test and people argue about it for months.

Foam request a quote covers roll, sheet, plank and fabricated sets. Foam pouch request a quote covers pouches and protective mailers.

Anti-static, and when ESD protection is actually required

Pink and black packaging gets bought on reflex for anything with a circuit board near it. Some of that is necessary and some of it is theatre, and the two are not distinguished by colour.

Three different properties are involved, and they are not interchangeable.

  • Anti-static means the material will not generate a charge when it rubs against itself or the product. It stops the packaging being the source of the problem. It does not protect against anything outside the bag.
  • Static dissipative means a charge placed on the material bleeds away in a controlled way rather than discharging all at once.
  • Shielding means a conductive layer forms a barrier around the contents so an external discharge does not reach them. That is the metallized bag, not the pink foam.

The mistake: assuming pink anti-static foam or pink bubble shields the part. It does not. It keeps the packaging from charging up. If an unprotected static-sensitive assembly is leaving a controlled area and travelling through a carrier network, shielding is the requirement — and the anti-static cushioning goes inside the shielding bag rather than instead of it.

When it is genuinely required: bare boards, unpackaged semiconductors, drives, sensors, and any assembly with exposed contacts or connectors. A finished product inside a grounded enclosure with no exposed pins is far less exposed. If your plant runs a formal ESD control program, the program document specifies the packaging and it outranks this article.

One question worth asking: whether the anti-static property is topical or permanent. Topical treatments sit on the surface, depend on ambient humidity to work, can lose effectiveness sitting on your shelf, and can transfer onto the product. If the packaging holds in inventory for a long time, or the product is sensitive to residue, get the type and the stated shelf life in writing.

Gauge, roll length and the ESD question are covered in more depth in the anti-static foam buying guide.

Paper: kraft, void fill and interleaving

Paper is where people go when a customer demands curbside-recyclable packaging, and then find it also solved a storage problem.

Kraft paper is specified by basis weight — heavier number, stiffer and stronger sheet. Light weights are for interleaving, wadding and wrapping. Heavier weights are for wrapping heavy or sharp-edged items, protecting surfaces in handling, and slip sheets. Rolls are sized by width and by roll diameter or weight, and the roll size your people can actually lift onto the dispenser matters more than the price per pound.

Void-fill paper is a lighter grade run through a machine that crumples or fans it into a low-density pad. The machine is what makes the economics work: paper on a flat roll is dense, cheap to store and cheap to freight in, and it only becomes bulky at the moment you use it. Bubble is bulky the entire way from the converting plant to the carton.

That is the real comparison. Per cubic foot of void filled, paper is usually more expensive in material and cheaper in everything else: storage footprint, inbound freight on the dunnage itself, and disposal at the receiving end. Bubble is cheaper per cubic foot of protection and costs you warehouse space all year. Which one wins depends on whether your binding constraint is material cost or floor space.

Use it for: void fill in cartons that are already close to the right size, interleaving between stacked parts, wrapping items where a bubble emboss would be a defect, wadding into corners, and any account that has told you it will not take plastic dunnage.

Where it fails: paper does not cushion a drop. Crumpled paper is compliant exactly once, and then it is packed flat. For real drop protection on a fragile item, paper fills the space around a foam or bubble cushion — it does not replace it. It is also heavy, so on a parcel already billed on actual weight rather than dimensional weight, switching to paper can raise the postage.

Paper request a quote covers kraft rolls, void-fill grades, sheets and slip sheets.

Honeycomb: bracing that does not need a chop saw

Honeycomb — Hexacomb is the name most shops use for it — is kraft paper expanded into a hexagonal cell structure, used bare or faced with linerboard. Loaded along the cell axis it is very strong in compression and very light for what it carries.

Use it for: edge and corner protection on panels, doors, glass, countertops and furniture; layer pads between stacked product on a pallet; blocks and runners that brace a heavy item inside a carton so it cannot migrate; and as a replacement for wood blocking where weight, cost or export treatment rules are a problem.

Where it fails: cushioning. It is rigid by design. Loaded across the cells or on a corner it crushes and does not recover. It also loses strength when it gets wet, so it is wrong for anything shipping uncovered or stored outdoors.

Where it wins on cost: anywhere you are currently cutting lumber to brace a load. Honeycomb blocking is lighter, it goes into the paper stream at the receiver instead of the skip, and it sidesteps the heat-treatment and marking rules that apply to solid wood packaging in export. If your shipping department owns a chop saw, this is the material to look at first.

Hexacomb request a quote takes the dimensions, the form — board, block, edge protector, corner post, layer pad — and the application.

Choosing by what you are actually shipping

Product profile How it fails What to use
Light, not fragile, box is bigger than the product Shifts in transit, box crushes in the stack Void-fill paper or loose fill. Then right-size the box and stop buying either.
Light and fragile — glassware, ceramics, labware Drop shock Several layers of 5/16" bubble, or low-density foam, plus corrugated cell dividers. Layers beat cell size.
Small, dense, easily marked — machined parts, hardware, instruments Surface damage and part-to-part contact Foam pouches or foam wrap. Bubble embosses soft finishes.
Static-sensitive electronics Discharge, and shock on top of it Shielding bag first, anti-static foam or bubble inside it.
Heavy and rigid — machinery, castings, motors Migration inside the carton, then puncture Honeycomb blocking and bracing. Cushioning is the wrong tool here.
Flat panels, doors, tops, glass Edge and corner damage Honeycomb edge protectors and corner posts, with foam or bubble interleaf between faces.
High value and fragile — instruments, finished assemblies Shock, and the cost of being wrong An engineered foam set designed off a cushion curve, in a right-sized double-wall carton. Test it before you run it.
Palletized mixed freight Layer collapse and load shift Honeycomb layer pads and edge protection under the strapping. Not a cushioning problem at all.

If the product is valuable enough that a failure hurts, drop-test the pack before you commit to it. A handful of sacrificial units settles the question that no amount of specification argument will.

The freight arithmetic nobody runs

  • Dunnage adds to every dimension twice. Two inches of foam on each face adds four inches to length, four to width and four to height. Parcel carriers bill on cubic size when it exceeds actual weight, so work out the billable weight of the pack you are proposing before you approve it, not after the first invoice.
  • On LTL it works against you through density. Freight classification is driven largely by pounds per cubic foot. Adding volume without adding weight lowers density, and lower density can move the shipment into a higher class. Cushioning that costs pennies per unit can cost real money in class on every skid.
  • Compare against the damage rate you actually have, not the one you are afraid of. Pull the credits and returns for the last year, count the units damaged, multiply by replacement cost plus the handling. If annual damage cost is smaller than the annual freight premium of the heavier pack, the heavier pack is the more expensive option even though it works.
  • Right-sizing the carton beats every material on this page. A box cut to the product needs less dunnage, weighs less, cubes less and costs less to fill. The correct first move on a damage problem is usually to change the box, not to add material inside the one you have.
  • Count the storage cube of the dunnage itself. Bubble and loose fill occupy floor space from the day they arrive until the day they are used. Paper on a roll and foam in plank do not. Price that space at whatever your building actually costs per square foot.

Box sizing, board grade and the pallet-pattern side of this are covered in the corrugated box buying guide.

What to have ready when you ask for a quote

  • What the product is, its weight, and its outside dimensions.
  • Its bearing area — the footprint it actually rests on. This is what sets foam density.
  • How fragile it is. A fragility rating in G is ideal; if you do not have one, describe what has broken before and how it looked.
  • How it ships: parcel, LTL, palletized, export, and how many times it gets handled.
  • The carton you use now — inside dimensions and board grade.
  • Your current damage rate and what the failures look like. Crushed corners, punctured walls and broken contents are three different problems with three different fixes.
  • Any requirement imposed on you: ESD program, recyclability, no plastic, export wood rules, cleanroom, food contact.
  • Annual volume and how you want it released.

Where Supply Tie fits

Supply Tie is a distributor. We buy this material direct from the plants that convert it, which means the recommendation is not steered by what happens to be in stock, and the specification conversation happens with the people running the extruder, the laminator or the converting line.

Bubble, foam, foam pouches, kraft and void-fill paper and honeycomb all quote through the same conversation, and in most cases the honest answer uses more than one of them — a shielding bag inside a foam set inside a right-sized box, or honeycomb blocking with a paper interleaf. Send the product, the weight, the carton you use now and the damage you are seeing, and we will spec it.

Related reading: the anti-static foam buying guide and the poly bag buying guide.

Shop this: foam and bubble packaging · bubble wrap and bubble bags. Related products: Bubble Reclosable Bags.

Back to blog