Peptide Boxes with Cardboard Insert

How a folded insert holds a vial

The usual construction is a raised deck: a flat sheet with a punched hole, supported above the box floor by folded legs at each end. The vial passes through the hole and its base rests on the box floor, so the deck grips the vial around its body or shoulder while the floor carries the weight.

Because paperboard does not compress, the hole cannot be an interference fit the way a foam cavity is. Instead the hole is sized so the vial passes through with minimal clearance, and small die-cut tabs around the perimeter flex slightly to hold it.

• Punched hole with relief tabs — Small radial cuts that flex against the vial and grip it lightly.
• Deck height — Set so the deck contacts the vial at its widest stable point, not at the neck.
• Folded legs — Support the deck and stiffen the whole insert; the number depends on the span.
• Cap clearance — The hole must be large enough for the cap to pass through during loading.

Insert structures we produce

• Raised platform — The standard single-piece deck. One flat blank, two or four folds.
• Folded partitions — Interlocking strips forming a grid of cells. Best for multi-vial cartons.
• Twin-wall partitions — Double-thickness cells for heavier vials, which also stiffen the carton.
• Wrap-around cradle — A folded shape supporting a vial lying on its side, for flatter packs.
• Laminated platform — Two bonded layers where a single sheet would be too flexible.

When paperboard is genuinely enough

This is the question worth answering honestly before spending on foam.

• The pack travels inside an outer case — The case takes the impact; the insert only needs to locate the vial.
• The vial is light — 2ml, 3ml and 5ml vials are well within what a folded deck can hold.
• The box is opened once — Repeated removal gradually widens a punched hole; a single opening does not.
• Recyclability matters — One material, one stream, no separation needed.
• Cost per unit matters — At volume the difference against foam is substantial.

Where any of those conditions do not hold — a heavy vial, a posted pack, a box opened weekly — EVA foam inserts are the better specification and we will say so.

Material choices

• SBS paperboard — White both sides. Clean interior appearance, folds crisply.
• Kraft paperboard — Brown, unbleached. Pairs naturally with a kraft carton.
• E-flute corrugated — For partitions carrying heavier vials, where the flute adds stiffness.
• Recycled board — Higher recycled content, with slightly less consistent folding behaviour.
• Coated board — A laminated or coated surface where the insert needs to resist marking.
• Matching the carton — An insert cut from the same grade as its folding carton keeps the pack in one material and one delivery.

Fibre direction matters more on inserts than on cartons. Folds running across the grain crack; folds running with it stay clean. It is one of the reasons we cut inserts rather than sourcing generic ones — the detail is covered on the packaging materials page.

Printing on inserts

A printed insert is one of the cheapest ways to add useful information exactly where the customer is looking.

• Cavity numbering — Position numbers printed beside each hole.
• Position labels — Short product names or codes for multi-product kits.
• Brand colour — A solid colour across the deck, which reads as a designed interior.
• Handling notes — Content you author and approve, printed on the visible deck surface.
• One-colour printing — Usually sufficient, and it keeps the insert cost close to plain board.

Which boxes take a paperboard insert

• Tuck end cartons — The natural pairing — both ship flat, both recycle together.
• Two-piece boxes — A platform drops straight into the base.
• Sleeve and tray — Partitions sit inside the tray with no adhesive needed.
• Corrugated shippers — Twin-wall partitions inside a transit case.
• Rigid boxes — Possible, though a wrapped board platform usually looks better in a premium build.

Ordering

• 1. Send the vial — Hole diameter is set from the cap and the body, and both need measuring.
• 2. Confirm the carton — The insert is cut to the carton interior, so the carton is specified first.
• 3. Structure selection — Platform, partitions or cradle, depending on count and vial weight.
• 4. Sample — A cut and folded sample with your vial seated in it.
• 5. Production — Printed if required, die-cut, creased and supplied flat.

Artwork and specification guidance

• Insert artwork goes on the insert die line, which is a different file from the carton die line.
• Remember which deck surfaces are visible once the insert is folded — some faces end up hidden.
• Keep printed detail clear of fold lines, where the ink can craze.
• Specify whether the insert is loaded by hand or on a line; it affects tab design.
• Supply insert artwork as print-ready PDF with outlined type and 300 dpi links.

Quality control

• Hole diameter is checked with a real vial, including cap pass-through.
• Fold quality is inspected — cracked folds indicate wrong grain direction.
• Deck height is verified so the insert grips at the intended point on the vial.
• Assembled inserts are loaded and the carton inverted as a movement check.
• Partition grids are checked for square.

Delivery

• Inserts ship flat, banded in counted bundles, alongside the cartons.
• Partitions ship flat and are erected during packing.
• Flat delivery keeps both freight and storage costs low.
• Nationwide delivery across the United States.