What actually sets the price of an LDPE bag

What a price is made of

The five levers, in the order they matter

1. Granule price (the one nobody controls)

LDPE granule is a petrochemical product. Its price moves with crude oil, with the rupee against the dollar, and with domestic supply from the big Indian producers. When granule moves 8 rupees a kilo, every honest converter in the country moves with it. This is why quotes are usually valid for a limited window, and why a supplier who promises a fixed price for a year is either hedging or planning to cut something.

2. Gauge (the one you control most)

Micron is a direct multiplier on the weight of plastic. A 60 micron bag uses 25 percent less material than an 80 micron bag of the same size. If your bag is over-specced, that is a permanent 25 percent saving sitting on the table. Over-specced bags are extremely common because nobody revisits a spec once it works. This is the first thing we look at on a comparison quote.

3. Size and shape

Every extra inch is more film. So is a gusset. So is a fold-over lip. And every bag bigger than the product it holds is film you paid for and threw away. Measure your three most-shipped items and order to fit them.

4. Print

Plates and setup are one-time per design, so print is a big adder on 200 kg and a small one on 2,000 kg. Colours also add up: each colour is a plate, a station and a register check. Two well-chosen colours usually look as intentional as four.

5. Volume and MOQ

The line has to be set up, purged and run whichever quantity you order. On a 100 kg lot, setup is a big share of the cost. On a 1,000 kg lot it is a rounding error. That is the whole reason MOQs exist, and it is why annual-rate commitments with monthly releases beat repeated small orders on price.

The bag-weight formula (use this before you accept any quote)

This is how you convert between per-kilo and per-piece, and how you check whether the bag you were sent is the bag you ordered.

For a flat bag

Weight per bag in grams = 2 x width (cm) x length (cm) x thickness (micron) x 0.92 / 10,000

The 2 is for both walls of the bag. The 0.92 is LDPE density in grams per cubic centimetre. The 10,000 just converts the units so the answer comes out in grams.

Worked example

A 16 x 24 inch bag is 40.6 x 61 cm. At 60 micron: 2 x 40.6 x 61 x 60 x 0.92 / 10,000 = 27.3 grams per bag. One kilo is therefore about 36 bags, and at a rate of 145 rupees per kilo that bag costs about 4.03 rupees.

Now run the same bag at 50 micron: 22.8 grams, about 44 bags per kilo, 3.30 rupees per bag. Same bag on paper, 18 percent cheaper per piece, and 17 percent less plastic between your product and the world.

And this is how you catch a gauge cut

Weigh 10 bags on a kitchen scale. Divide by 10. Compare against the formula. If the real weight is 10 percent under the calculated weight, the film is thinner than specified, whatever the invoice says. Every serious buyer we work with does this on the first delivery from a new supplier. We assume you will do it to us, which is a good reason for us to be straight with you.

How we quote, and why we will not publish a rate card

A published price per kilo for "LDPE bags" would be useless. It would not know your micron, your size, whether you print, how much you take a month, or where you are. Any number we put on a page would be either misleadingly low or embarrassingly high.

What we do instead: send the spec and get a firm number within one working day, showing the per-kg rate, the per-piece cost, the MOQ and the lead time. If the spec is wrong for the job, we say so before quoting. If a cheaper spec does the same work, we quote both and let you choose.

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