The insert sets the spacing between products, controls how they travel and shapes the moment someone lifts them out of the box. For a fragrance set or skincare kit, small decisions about a support tab, a cavity or a finger opening can change both the packaging experience and the amount of material required.

Choosing more sustainable box insert materials means connecting that design work with sourcing and what happens after use. Paperboard, corrugated board and molded fiber are useful starting points for many products. Plastic trays and foam also deserve consideration where their properties solve a meaningful problem. This guide covers structural packaging inserts—the trays, dividers and supports that hold, separate or cushion products inside retail, gift and ecommerce packaging.

Protection starts with the structure

Holding a product in place and cushioning it against impact are different jobs. Retention limits movement and collisions. Cushioning reduces shock by deforming in a controlled way. A rigid collar around a glass bottle may hold it securely while leaving its base exposed to impact through the box. Adding a suitable folded support beneath the bottle changes the protection; simply tightening the collar may not.

Contact points matter, too. An insert should support suitable parts of the product without concentrating force on a delicate pump, cap or projecting detail. A glossy surface can arrive unbroken but visibly scuffed if it rubs against an insert during transport. The opening experience adds another requirement: enough access to lift the product comfortably, without pulling on a closure or tearing the tray.

When we develop options at CMIC, we consider the product, insert, presentation box and transport packaging together. The insert does not have to supply all the shipping protection itself, but it must work with the outer packing that will actually be used. Replacing foam with fiber may therefore involve changing support points, clearances and the surrounding box.

Compare the main box insert materials

These are starting points for development. Material grade, thickness, geometry and the complete pack determine the finished result.

Folded paperboard: efficient structure and a clean presentation

Paperboard works well when the main task is to organize lightweight products and create a deliberate arrangement. Cut openings, folded feet and locking tabs can form a raised platform or separate cells. A set of lip balms, for example, can be held by a folded structure without filling the entire space beneath every item. The visible surface can also carry color, graphics or product information.

Thickness alone does not determine strength. A wide unsupported panel may flex, while folds and shorter spans help the same board carry a load. This makes structural development especially useful before moving to a heavier grade. Formats supplied flat can save storage space, although folding and loading time still belong in the cost comparison. A clever structure loses some of its appeal if packing each set becomes slow or awkward.

Corrugated board: separation with room for protective folds

The fluted layer inside corrugated board gives designers depth to form supports, partitions and crushable spaces. It is useful for jars, bottles and gift sets that need more support than a simple paperboard platform provides. A folded base can lift a glass jar away from the bottom panel, while partitions keep neighboring jars apart. A flat divider provides separation, but it does not automatically cushion the underside of either jar.

Board grade, flute direction, folds and clearances all affect performance. Appearance can be developed through the structure as well: folded edges can conceal exposed flutes, and a printed paper facing can give the opening a more finished appearance. Compare the assembled result, including its depth and packing time. A protective structure that forces a larger outer box may change both freight cost and material use.

Molded fiber: a shaped cradle with its own character

Molded fiber, also called molded pulp, forms fibers into a three-dimensional part. Feedstocks can include recovered paper, virgin pulp or agricultural fiber such as bagasse, a residue from sugarcane processing. A shaped tray can support curved products and organize several items with fewer separate components. The feedstock name alone does not establish recycled content, protective performance or disposal suitability.

Forming and finishing methods can produce visibly textured surfaces or smoother finishes. That gives molded fiber more visual range than the familiar egg-carton appearance suggests. A production-representative sample should establish the surface, color and contact with the product. Against a dark, glossy bottle, even a small amount of rubbing may matter more than the tray’s appearance when empty.

Tooling brings an initial investment and makes later cavity changes consequential. Sloped walls and rounded transitions may be needed for forming and release, so a foam cavity is rarely a drawing to copy unchanged. Nesting can make empty trays efficient to store and transport, but compare actual packed quantities. The worthwhile comparison includes tooling, planned volume, product versions and the finished pack dimensions.

PET and recycled PET: thin, defined trays

Thermoforming shapes a heated plastic sheet into cavities and supports. PET—polyethylene terephthalate—is one common material; rPET means recycled PET. These trays can combine low weight, defined product positions and clarity. Their moisture resistance can also be useful, although an open tray does not seal the product against moisture. Ribs, wall geometry and contact points still need to provide the required protection.

NAPCOR explains that PET thermoforms are technically recyclable with PET bottles, subject to sorting and reclaimer requirements. That establishes a possible material route, while local collection and the finished tray design determine its practical relevance. Specify the resin and recycled-content percentage, and make the tray easy to remove from the paper box. A bonded decorative construction needs a different assessment from a simple, removable tray.

Foam: specify the material behind the appearance

Foam earns its place when it supplies cushioning, surface protection or resilient grip that a simpler structure cannot readily provide. The specification needs more than “black foam”: polymer, grade, density, thickness and cavity geometry affect behavior. An overly soft pad can compress fully under a heavy product, leaving little movement available to cushion an impact.

• EPE, expanded polyethylene: flexible cushioning used in pads, shaped supports and protective sheets.
• EVA, ethylene-vinyl acetate: available in grades suited to defined cut cavities and a tidy presentation, including jewelry and watch inserts.
• PU, polyurethane: flexible grades can conform around delicate products; firmness and load support need to suit the application.
• EPS, expanded polystyrene: lightweight, rigid molded supports with useful cushioning, but a brittle structure that can fracture or shed beads.
• EPP, expanded polypropylene: resilient molded foam worth considering where repeated handling and reuse are part of the intended system.

Where foam is needed, test whether smaller removable pads can do the work of a full block. Recovery claims should identify the exact foam and route: a specialist collecting clean factory offcuts does not establish a household route for a used insert. Fabric facings, flocking and adhesive layers also change what the receiving recycler must handle.

Mycelium and starch-based options: evaluate the finished formulation

Mycelium—the network of fungal threads—can bind plant residues into molded structures. It offers an interesting combination of shaped support and distinctive texture, but performance varies with the feedstock and process. Starch-based cushioning also covers different formulations and formats. Loose fill, for example, fills voids without providing the defined positioning of a fitted tray. For these options, examine finished samples for fit, surface contact, moisture response and consistent production. Additives, binders and coatings can change both performance and the intended disposal route; the plant-based ingredient is only part of the specification.

Judge sustainability across the whole pack

Reduce material and space together

Removing unnecessary depth, hidden filler layers or duplicate partitions can be as useful as changing materials. Compare the insert alongside any extra wrapping, the presentation box and the shipping carton. A lighter insert that requires another protective layer or a larger shipper has changed the system, so the insert’s weight alone cannot describe the improvement. Protection remains part of that comparison: damaged products bring wasted product, replacement packaging and additional transport.

If carbon reduction is the objective, compare complete packs delivering the same products with equivalent protection. Material production, forming or drying, factory energy, manufacturing waste, transport volume and disposal assumptions can all change the result. A footprint quoted per kilogram of material cannot rank two insert designs by itself when they use different quantities or need different outer packaging.

Separate recycled content from sourcing and recyclability

Recycled content describes material inputs. Ask for the percentage by weight of the specified component and whether the recovered material comes from manufacturing waste, consumer use or both. An insert’s percentage does not automatically describe its decorative covering or the whole box. Color and texture are design choices; neither provides reliable evidence of recycled content.

FSC’s labeling system addresses sourcing. It serves a different purpose from a recycled-content statement or an assessment of the finished insert’s recyclability. Keep those questions separate when comparing paper grades: where the fiber comes from, how much recovered material is used, and whether the completed construction fits the intended recovery system.

Design for the route after opening

A practical recycling route needs collection, successful sorting and a processor able to use the recovered material. For packaging manufactured in China and sold overseas, household disposal conditions belong to the destination market. A route for production scrap near the factory says little about what the final customer can place in local collection.

For fiber inserts, the recycler needs to recover usable fibers from the finished construction. Some inks, coatings and adhesives are compatible with paper recycling; others complicate processing or reduce recoverable fiber. A paper facing and a plastic-film laminate are different constructions, even when both are described as “laminated.” Bonded fabric adds another material again. Removing an unnecessary covering—or making a necessary component easy to lift out—can simplify disposal as well as assembly.

Plastic recovery is also sensitive to design. The APR/FPI guide to North American plastics recycling explains how shape, colorants and attachments can affect sorting and reprocessing. Some dark pigments interfere with optical sorting. A resin identification code identifies the plastic; it does not establish local acceptance of the particular tray. These details make recovery easier to consider while the design is still adjustable.

Give compostability and reuse a practical purpose

Compostability has practical value when the finished insert suits a defined composting process and customers can actually use that route. Evidence should cover the complete formulation, including coatings and adhesives. Industrial compostability does not establish home compostability, and a plant-based material is not automatically suitable for either. For a clean, dry retail insert, an accepted paper-recycling route may be more practical than introducing a separate composting route.

Reuse also needs a believable purpose. A watch insert may continue to support the product in its storage box; a cavity for a disposable miniature bottle may have little use after the bottle is empty. Design around that onward use. Where packaging is intended for repeated shipping cycles, durability, cleaning, return transport and the number of completed uses belong in the comparison.

Describe the specific improvement

Useful claims identify the component and the evidence: its verified recycled-content percentage, or a measured material reduction against a named previous version. For US-facing marketing, the FTC’s Green Guides summary advises against broad, unqualified claims such as “eco-friendly.” It also says recyclable claims should be qualified when appropriate facilities are unavailable to at least 60 percent of consumers or communities where the product is sold, with stronger qualification as access becomes more limited. Collection access is one requirement; the finished insert must also be suitable for that recycling route.

A fragrance set shows why geometry matters

Consider a glass fragrance bottle and travel spray in a rigid gift box, shipped inside a courier carton. The aim is to replace a full-depth foam block while preserving the calm, precise presentation. A folded paperboard deck can locate both products, but if the bottle rests directly on the box base, the deck has not replaced the foam’s cushioning function. A corrugated cradle could instead raise the bottle, support its body and keep the spray separate. A finger opening lets the recipient lift the bottle by its body without tugging on the cap.

The next comparison concerns the finished pack: whether the support survives transport, whether contact marks the bottle decoration and whether loading is straightforward. If a small protective pad remains necessary, it can be assessed as a removable component. For a stable, repeated product layout, a molded-fiber tray offers another construction to compare. The same brand’s lightweight tube set may need only a folded paperboard platform. A consistent visual identity can accommodate different protective structures.

Compare finished samples and total cost

At CMIC, we can turn an aim such as “remove the full foam block while keeping this opening experience” into a small number of structural options. Product samples or dimensions, weights, sensitive surfaces, sales destinations and expected quantities give that comparison a useful basis. We can develop paper structures and coordinate suitable molded, plastic or foam options where needed. The intermediate result should be something you can handle and compare, with the significant differences explained.

Compare cost at the planned order quantity, including tooling, samples, material, assembly, loading, packing volume and likely version changes. A low unit price can be offset by labor-intensive folding. A formed tray’s tooling may be easier to justify across a stable production run, while frequent changes to kit contents can favor a more adaptable construction. Neither material name nor an isolated piece price resolves those differences.

• Fit and handling: use actual products, account for size variation, and check loading, retention and removal.
• Surface and climate: examine rubbing, marking and performance under relevant storage and transport conditions, including humidity where it matters.
• Distribution: assess the complete shipping pack using an appropriate combination of drop, vibration and compression testing.
• Production consistency: compare samples representative of the intended materials and process, with dimensions, tolerances and finishes defined.

Agree what a successful result looks like before approval. An intact product can still have unacceptable scuffs, a loose closure or an insert that collapses during removal. We can help coordinate the relevant validation and bring the approved structure, material specification and sample into alignment. That gives purchasing, production and quality teams a shared reference for the result you selected.

If you have a product or an existing pack in mind, talk with us about the insert. Bring the protection problem, the opening experience you want and the markets where the product will be sold. Those details give us a useful starting point for developing a simpler, well-supported material choice.