The specs that decide whether the bag survives
Supermarket bag programmes fail in predictable ways: the handle splits at the punch, the side seam opens under a heavy load, or the bottom seam gives out when the bag is set down on a wet floor. Every one of those failures traces back to a specification that was left vague at the buying stage.
This guide covers the four specifications worth being precise about, and the three that usually are not.
1. Handle tensile strength
This is the number that matters most and the one most often left as 'strong handles'. Specify it as a minimum force in newtons that the handle assembly must survive without separation or tearing, tested on the finished bag rather than on fabric swatches.
For a standard grocery programme carrying up to 8 kg, we recommend specifying the handle assembly to hold a static load of at least 15 kg — roughly double the intended payload — applied for a sustained period rather than a momentary pull.
Also specify the test method. A one-second burst pull and a sustained hold are very different requirements, and a supplier optimising for the wrong one will pass the wrong test.
2. Heat-seal strength on the gusset and base
The bag failing at the side seam is more common than the handle failing, and it is entirely a heat-seal problem. Ultrasonic or high-frequency sealing produces a bond that is stronger than the surrounding fabric; a poorly tuned thermal seal produces a bond that is weaker.
Specify the seal width in millimetres, the number of sealing ribs, and the peel strength in newtons per 25 mm. A bag under 8 kg should show no seam separation under a rated static load with a visible safety margin.
If your volume justifies it, ask for seal-strength data on your actual material and GSM combination — not a generic certificate from a different substrate.
3. Bottom load capacity
The base of a grocery bag carries the load while the bag is stationary, and it fails through a burst rather than a tear. Drop-test ratings exist for this, and they are worth specifying if your bags carry heavy or wet goods.
For most programmes, a simple bag-drop test with a specified payload and drop height is sufficient and far more meaningful to a supplier than a laboratory certificate.
4. GSM and the ±5 tolerance
Specify fabric weight as a minimum with an explicit tolerance, as discussed in our GSM guide. A supplier who can hold a tolerance will welcome the specification. One who cannot will quietly ship the bottom of the band.
What you can ignore
Grade numbers for fabric softness, subjective colour-appearance language that does not reference a standard, and 'eco-friendly' without a defined attribute are all specification noise. They consume review time and resolve nothing.
Instead, specify Pantone references for print, dimensional tolerances for the finished bag, and a clear artwork approval process. Those are the specifications that produce a shipment your store teams can put straight on the shelf.
Getting to a quotation in 24 hours
A complete specification sheet for a bag programme is short: bag style, GSM with tolerance, size range, print colours and coverage, handle type, lamination requirement, and quantity per size. Send those seven items and you will have a defensible price the same day.
If a supplier asks for more than that before quoting, they are likely building a sample run first — which is fine, but you should know that is what is happening.