Supply notes Layered
Tape Runner Adhesion Test
Four tape runners on six surfaces, pulled at 90 degrees with a luggage scale. The strongest runner is not the one that holds best — it is the one that fails at the highest load without tearing the paper.
8 layers 7 min
Measuring instead of guessing
Tape runners get judged by how they feel when you press them down, which tells you nothing about the bond. A luggage scale clipped to a 25 mm wide sample gives an actual number in kilograms, and the number is repeatable to about 5%. Pull at 90 degrees, at a steady 20 mm per second, and record the peak rather than the average.
Strongest is not best
The strongest runner peaked at 4.1 kg on 250 gsm card and tore the paper at 3.6 kg — the bond outlasted the substrate, which is a failure. The runner that behaves best peaks just below the tear strength of whatever it is stuck to, so it releases before the paper does. On 110 gsm kraft that means a peak around 1.6 kg.
Tissue is the real test
On 17 gsm tissue, every runner exceeded the paper's own strength: all four tore the tissue before releasing, at 0.3 to 0.6 kg. There is no runner that behaves well on tissue, which means the answer for tissue is not a better runner but a different adhesive — wheat starch paste, applied with a brush, where you control the film thickness instead of accepting whatever the manufacturer rolls on.
Where the runner wins
Runners are unbeatable for flat, dry, medium-weight bonds at speed: mounting a 120 gsm photo mat to board, closing a pocket, holding a test position while you decide. They are the wrong tool for anything you might need to lift, anything thin, and anything that will live in a humid room. Keep both a runner and a paste pot on the desk.
Assembly order
- 1Cut 25 x 100 mm samples of each surface and tape them to a rigid board.
- 2Run a single strip of runner down the middle and burnish 15 seconds.
- 3Fold the free end back 180 degrees and clip the scale to it.
- 4Pull at 90 degrees at 20 mm per second and record the peak.
- 5Note whether the paper tore or the bond released, and at what load.
About 7 minutes of bench time, plus whatever the adhesive needs.
Supplies
- Four tape runners permanent, 6-9 mm
- Six test surfaces tissue to 250 gsm card
- Luggage scale 0-50 kg, 10 g resolution
- Steel rule for the 90 degree pull rig
- Bone folder for uniform rub-down
Peak 90-degree peel force, 25 mm samples, and what failed first
| Surface | Strongest runner | Best-behaved runner | Failed first |
|---|---|---|---|
| 17 gsm tissue | 0.6 kg | 0.3 kg | paper, all four |
| 60 gsm text | 1.1 kg | 0.7 kg | paper on two |
| 110 gsm kraft | 2.4 kg | 1.6 kg | bond |
| 250 gsm card | 4.1 kg | 2.7 kg | paper on the strongest |
Where this goes wrong
Runner adhesive gets stronger for about two hours after application and then plateaus, so a sample tested immediately reads about 30% lower than a sample tested the next day. Test everything at the same age or the comparison is meaningless.
