A 20 kg carton goes through three sorting hubs, and at the customer's warehouse its bottom splits open along the seam: the tape has let go and the goods arrive in a damaged box. This almost always means the tape was chosen by the price of the roll rather than by the weight of the box and the route. This guide explains how reinforced gummed tape differs from non-reinforced water-activated tape and plastic tape, how to choose the right type and width for the carton weight, and how to apply it properly.
What reinforced gummed tape is
Gummed tape, also called water-activated tape (WAT), is kraft paper coated with a dry starch-based adhesive. Dry, it is not sticky. Once moistened, the adhesive soaks into the fibres of the corrugated board, and as it dries the tape effectively becomes part of the box. It cannot be peeled off neatly: the top layer of the board comes away with it.
In the reinforced version, fiberglass threads are laminated between layers of kraft paper. They run along the tape and, in many constructions, also diagonally or across it, forming a mesh. The threads stop the tape from splitting lengthwise or stretching when a heavy load pushes on the flaps. That is why one correctly applied strip is often enough where plastic tape would need two or three passes.
Viskom stocks reinforced kraft tape in two roll lengths: Stabil 60 mm × 200 m and Optimal 60 mm × 150 m. According to the product specifications, both use 60 g/m² paper and a starch adhesive and are rated from −20 to +60 °C. Both are sold by the roll and in packs of 8.
Reinforced, non-reinforced or plastic tape: the differences
All three close a carton, but they work in different ways. Here is a quick comparison.
| Feature | Reinforced gummed tape | Non-reinforced gummed tape | Plastic tape (PP, acrylic) |
|---|---|---|---|
| How it holds | Adhesive soaks into the board, threads carry the load | Adhesive soaks into the board | Adhesive sits on the surface |
| Tensile strength | High, does not split lengthwise | Medium, may crack on a heavy box | Depends on film thickness |
| Tamper evidence | Visible: the board tears | Visible: the board tears | Can be peeled off carefully and re-applied |
| Needs water | Yes | Yes | No |
| Best for | Heavy cartons, parcel carriers, export | Light cartons, palletised loads, short routes | Quick packing without equipment, internal moves |
We compared water-activated and self-adhesive paper tape in a separate article, Water-Activated or Self-Adhesive Kraft Tape. Here we focus on reinforcement and carton weight.
When you need reinforced tape
Heavy and overfilled cartons
The heavier the box, the harder the contents push on the bottom flaps, especially when a parcel is dropped onto a sorting conveyor. Non-reinforced tape can crack along the seam, while the threads in reinforced tape carry the load. The same applies to overfilled boxes whose flaps are pushed outwards from inside.
Parcel networks and export
A single carton in a carrier network goes through several sorts, transfers and stacks. International shipping adds swings in temperature and humidity. On these routes, reinforced tape is more reliable than any unreinforced tape. A pallet wrapped in stretch film is different: the cartons do not pull individually, so non-reinforced tape is often enough.
Tamper evidence
Gummed tape, reinforced or not, cannot be removed without trace because the board tears with it, so it works as a seal. If you also want a visible warning for the recipient, combine reinforced tape with tamper-evident kraft tape or printed tape. All the ways to protect a shipment are covered in How to Stop Package Tampering.
How to choose the type and width for the carton weight
There is no single standard: manufacturers grade reinforced tapes in their own way. In the Central range from Intertape, for example, grade 250 is recommended for cartons up to 40 lb (about 18 kg) and grade 280 for cartons up to 90 lb (about 40 kg). In other words, reinforced tape is chosen by carton weight.
The table below is a practical guide, not a standard. Always confirm your choice with a test batch using your own boxes and products.
| Carton weight and route | Tape type | How to apply |
|---|---|---|
| Up to ~5 kg (11 lb), single-wall board | Non-reinforced, 40–60 mm | One strip over the seam with legs down the sides |
| 5–15 kg (11–33 lb), pallet or short route | Non-reinforced, 60 mm | One strip on top and one on the bottom |
| 5–15 kg (11–33 lb), single parcel via a carrier | Reinforced, 60 mm | One strip on top and one on the bottom |
| 15–30 kg (33–66 lb) | Reinforced, 60 mm | Strip with 5–7 cm legs; two strips on the bottom are advisable |
| Over 30 kg (66 lb), double-wall board, export | Reinforced, 60 mm | H-seal: seam plus cross strips on the ends; add strapping if needed |
Width. The general rule in packaging guides is simple: the wider the box and the more the flaps bulge, the wider the tape should be. Boxes up to about 38 cm (15 in) wide usually need 48–50 mm tape; for wider boxes, guides recommend tape of about 70 mm. Viskom's reinforced tape is 60 mm wide, so on very wide or overfilled cartons add a second strip or use an H-seal.
For light shipments there are non-reinforced rolls of 60 mm × 200 m, as well as 40 and 50 mm. The full range is in the water-activated kraft tape category.
How much tape one carton needs
You can work out consumption in advance to see how many boxes a roll will seal. One strip equals the length of the seam plus two legs down the side walls.
Example. A 40 × 30 × 30 cm box, seam along the long side, legs of 6 cm. Top strip: 40 + 6 + 6 = 52 cm. The bottom is the same, so about 1.04 m per box. A 200 m roll will then seal roughly 190 boxes, and a 150 m roll roughly 140.
If you H-seal the bottom of a heavy box, add two cross strips on the ends: 2 × (30 + 6 + 6) = 84 cm. Consumption rises to about 1.9 m per box, and a 200 m roll covers roughly 105 boxes. This is an estimate: check the actual strip length on your dispenser, as some models cut with an allowance.
Paper weight: what it affects
Kraft paper weight (g/m²) affects how stiff and puncture-resistant the tape is. For reinforced tape, though, the construction matters more: how many threads there are and how they are laid. When comparing suppliers, look at paper weight, reinforcement type and recommended carton weight together. Viskom's reinforced tapes use 60 g/m² paper.
Dispensers for reinforced tape
You can wet reinforced tape with a sponge, but on a busy packing bench this is slow and uneven: some areas dry out, others get too wet. A dispenser solves both problems by moistening the adhesive evenly and cutting the strip.
- MiniTaper is a manual dispenser with a water tank and rollers that spread water across the tape. It takes rolls up to 80 mm wide and suits a small shop or a single packing station.
- Alpha X1-400 is an automatic dispenser that measures, moistens and cuts the tape at the push of a button. According to the manufacturer, it handles tapes 50–80 mm wide, from 40 g/m² paper to reinforced grades. It pays off where dozens of cartons are packed every day.
Fiberglass blunts simple blades quickly, so cut reinforced tape in a dispenser rather than with a knife. See all models in the water-activated tape dispensers section, and read Tape Dispenser: An Efficient Tool for Packing Work for general advice.
How to seal a carton: step by step
- Prepare the box. Fill any voids so the flaps lie flat, neither sagging in nor bulging out. The surface should be dry. Starch adhesive copes with light dust, but not with film or gloss lamination.
- Set up moistening. Fill the dispenser's water tank. Many manufacturers recommend warm, not hot, water because it speeds up activation.
- Measure the length. The strip should cover the whole seam and run 5–7 cm down each side. These legs hold the flaps when the box is lifted from the bottom.
- Apply the tape centred on the seam. The adhesive should look glossy and evenly wet, with no dry streaks or drips.
- Press with your palm. Rub from the centre outwards so the adhesive gets into the fibres, including on the side walls.
- Repeat on the bottom. For cartons over 15 kg, close the bottom with two strips or an H-seal.
- Let it dry. The tape grabs within seconds, but wait for the adhesive to set before stacking a heavy box on a pallet.
Common mistakes
- Too little or too much water. Dry adhesive will not bond, and excess water soaks the board so the adhesive runs.
- Short legs. A strip that covers only the seam is the main reason bottoms burst open.
- Non-reinforced tape on a heavy parcel. Saving on the roll ends up costing a return and damaged goods.
- Glossy or laminated boxes. The adhesive has nothing to soak into. Test on a sample or tape over unlaminated areas.
- Storing rolls in a damp room. Humidity starts to activate the adhesive and the layers stick together. Keep rolls dry and wrapped.
- Cutting with a knife. The reinforcement tears unevenly, the edge frays and holds less well.
If you ship fragile items as well as heavy ones, see our step-by-step guide to packing fragile items.
FAQ
Can I apply reinforced tape without a dispenser?
Yes, by wetting the adhesive with a damp sponge or brush. That is fine for a few boxes a day, but at volume a dispenser gives even moistening and saves time.
Is a carton sealed with reinforced tape recyclable?
The paper and starch adhesive are recycled together with the board. Reinforced tape contains fiberglass threads, so it is not 100% paper. If an all-paper pack matters to you, use non-reinforced tape on light cartons.
What is the difference between Stabil and Optimal?
According to the product specifications, both are 60 mm wide with 60 g/m² paper; they differ in roll length: 200 m for Stabil and 150 m for Optimal. For a more detailed comparison, ask a Viskom manager.
Does gummed tape hold in freezing temperatures?
Viskom's tapes are rated from −20 to +60 °C. Apply the tape indoors where it is warm; sealed cartons can then be stored and shipped in the cold.
Can I order reinforced tape with my logo?
Yes. Viskom offers reinforced kraft tape 60 mm × 50 m with a custom logo. The minimum order for your own design is 10 rolls.
Summary
Non-reinforced gummed tape is enough for light cartons and palletised loads. For single parcels from 5–10 kg, overfilled boxes and export, choose reinforced tape and apply it with legs down the side walls. A dispenser keeps moistening even and packing fast.
You can choose rolls for your cartons in the water-activated kraft tape category. Not sure which tape you need? Send Viskom the weight and size of your carton and the shipping route, and we will suggest an option and, if needed, a test batch.
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