Supply notes Layered
Glue Stick Showdown: Three Adhesives
A washable school stick, an acid-free archival stick and a repositionable stick, tested on five paper types over 72 hours for curl, bleed-through and whether the bond survives a humidity swing.
5 layers 7 min
The three failure modes
Every glue stick fails in one of three ways. Curl: the water in the adhesive swells one side of the paper and it cups. Bleed-through: water carries dye or the adhesive itself through a thin sheet. Debond: the film stays tacky but stops holding when the humidity moves. Which failure you get depends far more on your paper than on the brand.
What 72 hours showed
On 17 gsm tissue all three sticks cupped the paper by more than 12 mm and the school stick bled a faint blue line visible from the front. On 250 gsm card none of them curled measurably and all three held. The interesting result was in the middle: at 110 gsm kraft under a humidity swing from 38% to 68%, the repositionable stick released entirely within 20 hours, while the archival stick held.
Pressure matters more than amount
Doubling the amount of glue changed debonding by almost nothing. Doubling the rub-down pressure cut curl by 40%. A glue stick works by wetting and pressing the two surfaces into contact; extra adhesive just adds more water and more space between the sheets. Rub down with a bone folder from the centre out, 15 seconds per 100 mm square, and use the minimum glue that covers the area.
When to abandon the stick entirely
For anything under 25 gsm, skip sticks and use wheat starch paste applied with a brush at about 0.05 mm — the brush puts down a fraction of the water a stick does. For anything that will sit in a humid room for years, use PVA applied at the perimeter only. The glue stick is the right tool for 80 gsm to 160 gsm paper stuck to board, which is most of what a journal spread actually is.
Assembly order
- 1Cut five 50 x 50 mm samples of each paper and label the backs.
- 2Apply the minimum glue that covers the area, in two crossing passes.
- 3Place, then burnish from the centre outward for 15 seconds per sample.
- 4Measure the corner lift with a steel rule at 10, 20 and 60 minutes.
- 5Move the board into a 68% humidity box for 20 hours and check the bond again.
About 7 minutes of bench time, plus whatever the adhesive needs.
Supplies
- Washable school glue stick 8 g, blue-tinted
- Acid-free archival stick 10 g, pH 7.0-8.5
- Repositionable stick 8 g, low tack
- Five test papers 17-250 gsm
- Digital hygrometer 0.1% resolution
Curl across paper weights, 20 minutes after gluing
| Paper | School stick | Archival stick | Repositionable |
|---|---|---|---|
| 17 gsm tissue | 14 mm | 12 mm | 12 mm |
| 60 gsm text | 7 mm | 6 mm | 5 mm |
| 110 gsm kraft | 3 mm | 2 mm | 2 mm |
| 250 gsm card | 0.4 mm | 0.3 mm | 0.3 mm |
Where this goes wrong
Do not judge a glue stick by how it feels when wet. A stick that feels tacky on the finger is often the one with the most water in it, which is exactly the one that curls thin paper worst.
