Guides
How to choose paper GSM
GSM is the weight of one square metre of paper, in grams. Start from the job, then pick the grade, then the weight.
01 / The measure
What GSM measures
GSM stands for grams per square metre. Cut a sheet one metre by one metre, weigh the sheet, and the result in grams is the GSM.
GSM measures weight, not quality. A heavier sheet is not a better sheet. A heavier sheet is a different sheet, suited to a different job.
GSM also differs from thickness. Two papers at the same GSM feel different in the hand when their density differs. Our guide on GSM vs thickness covers this in detail.
02 / Our range
The KEIKO PAPERS weight range
- 35 GSM
- 120 GSM
03 / By grade
Weights by grade
| Butter paper rolls and sheets | 35–50 GSM |
|---|---|
| White and brown OGR | 35, 45, 55, 65, 70 GSM |
| White and brown MG | 40–80 GSM |
| White MF | 40–80 GSM |
| Kraft and bleached kraft | 60–120 GSM |
04 / Start here
Start from the job, not the number
The job decides the grade before the weight. A burger wrap needs a grease barrier. A tray liner needs clean release. A carton liner needs strength. Each of these points to a different grade.
Once you know the grade, the weight follows the handling. Across our ranges, lighter GSM suits wrapping and high volume. Heavier GSM suits handling and heavier product.
Weight never turns one grade into another. A heavier general-purpose sheet still lacks the grease barrier of OGR, and a heavier butter paper still lacks the tear strength of kraft.
05 / By job
GSM by job
Butter paper, 35 to 50 GSM, on the roll or as pre-cut sheets.
White or brown OGR, from 35 GSM for light wraps up to 70 GSM.
White or brown MG, 40 to 80 GSM, glazed on the printing face.
General wrapping and interleaving
White MF, 40 to 80 GSM, even on both sides.
Industrial wrap, void fill and sacks
Kraft, 60 to 120 GSM, long-fibre and unbleached.
Bleached kraft, 60 to 120 GSM, with a clean white surface.
06 / Cost
How weight changes cost
We price reels by weight. At the same width and length, a heavier GSM puts more kilograms on the reel, so the same length costs more.
For high-volume wrapping, every gram per square metre adds up across thousands of wraps. Buyers of OGR usually run high volume, which is why the lighter OGR weights are the point, not a compromise.
Work the other way too. A reel of fixed weight holds fewer metres at a heavier GSM. Our roll length calculator turns weight, GSM and width into metres, so you compare quotes on the same basis.
07 / Testing
How to test a weight before you buy
Order samples in two or three weights close to your choice. We send swatches before a first order in a new grade, and a swatch of a grade we hold costs nothing.
Test each sample on the real job. Wrap your own food, line your own trays, run a few sheets through your own machine.
Hold the samples to the light and compare the feel in your hand. Then pick the lightest weight passing every test, and record the choice on a specification sheet.
08 / Quotes
GSM on a quote and an order
Every quote line names the grade, the GSM and the format. Our MOQs apply per GSM and per width or sheet size, so each extra weight adds a line with its own minimum.
Keep the number of weights low. One or two weights per grade keep each line above the minimum and keep your stock simple.
Need a weight outside our listed range? Often we match a specific GSM. We hold the listed grades most consistently and indent anything outside the range to order, with the lead time quoted up front.
09 / Mistakes
Common GSM mistakes
Buying on weight alone. A heavier paper in the wrong grade still fails the job.
Comparing pound figures with GSM. US basis weights use pounds per ream at a basic size, and the basic size changes with the paper type. Convert before you compare.
Skipping the sample. A number on a quote tells you the weight. Only a sample on your own job tells you the fit.
10 / Further reading
Where to go next
The pages in this guide cover each weight question in detail: the GSM and sizes of butter paper and OGR, how weight differs from thickness, which GSM suits food wrapping, how basis weight converts to GSM, and how to work out roll length from weight.
11 / Formats
GSM across rolls, sheets and reams
The same GSM comes in different formats. Butter paper at 35 to 50 GSM comes on retail rolls of 25 to 100 m, bulk reels of 500 to 2,000 m, and pre-cut sheets.
OGR comes on reels from 300 to 1,200 mm wide, slit to order, and as sheets in three sizes. MG and MF come on reels from 500 to 1,500 mm wide and as sheets in two sizes. White MF also sells by the ream.
Each format has its own MOQ. Butter paper rolls start at 1 retail roll, or 250 kg per width and GSM in bulk. Sheets start at 10,000 per size and GSM. Pick the format with the weight, since MOQ and lead time differ by format.
12 / Food contact
GSM and food contact
Weight does not decide food contact. The grade does. Butter paper and OGR go against food at any of their weights.
White MF and kraft are not for direct food contact. For MG and bleached kraft, ask us before food use.
13 / By trade
Typical weights by trade
Bakeries line trays with butter paper across the 35 to 50 GSM range and wrap oily items in OGR.
Cloud kitchens and food counters wrap fried items in OGR at the light end, since every order uses a sheet.
Garment units interleave with white MF and fill cartons with kraft, where the heavier kraft weights take rough handling.
Bag makers print on MG at 40 to 80 GSM and turn to kraft where tear strength decides.
On this topic
Every page in this guide
Guides
- GSM vs thickness
GSM measures weight per square metre. Thickness, or caliper, measures depth. See how the two relate through density, and how to measure both.
- Paper sheet size chart
A paper sheet size chart for Indian buyers: ISO A sizes in mm, the old British sheet names, and every sheet size KEIKO PAPERS supplies, grade by grade.
- Which GSM for food wrapping
Which paper and GSM to use for food wrapping: oily food, baked goods, rotis and sandwiches. Grade first, weight second, with the food-contact limits of each grade.
Glossary
- Basis weight
Basis weight is pounds per 500-sheet ream at a basic size. GSM is grams per square metre. See how the two differ and how to convert a figure.
- Deckle
Deckle is the usable width of the paper web a machine makes. See where the word comes from and why the deckle matters when you order reel widths.
- Ream and reel
A ream is a pack of 500 sheets. A reel is one continuous roll of paper. See how each is priced and when to order reels, sheets or reams.
Specifications
- Butter paper GSM and sizes
KEIKO PAPERS supplies butter paper at 35 to 50 GSM. See every roll width, roll length and sheet size, with MOQs and lead times for bulk orders.
- Kraft paper GSM for packaging
Kraft and bleached kraft from KEIKO PAPERS run from 60 to 120 GSM. See reel widths, roll lengths, sheet sizes and MOQs, and how to pick a packaging weight.
- MG and MF paper GSM
White MG, brown MG and white MF paper from KEIKO PAPERS run from 40 to 80 GSM. See widths, roll lengths, sheet sizes, MOQs and which weight suits which job.
- OGR paper GSM
KEIKO PAPERS supplies white and brown OGR paper in 35, 45, 55, 65 and 70 GSM. See widths, roll lengths, sheet sizes and how to pick a weight.
Tools
- GSM calculator
Enter the GSM and sheet size to see how many sheets are in 1 kg of paper. The formula, a worked example and the reverse sum for GSM sit under the calculator.
- Paper roll length calculator
Work out how many metres of paper a roll holds from its weight, GSM and width. The formula and a worked example sit under the calculator.
Questions
Before you specify
Is a higher GSM always better?
No. GSM measures weight, not quality. Pick the weight the job needs.
What GSM is butter paper?
Our butter paper runs from 35 to 50 GSM, on the roll and as pre-cut sheets.
What GSM is kraft paper?
Our kraft and bleached kraft run from 60 to 120 GSM.
Do you supply a GSM outside your listed range?
Often. We hold the listed grades most consistently. We indent anything outside the range to order, with the lead time quoted up front.
How do I check the GSM of paper I already have?
Cut a square of 10 cm by 10 cm, weigh the square on a fine scale, and multiply the grams by 100.
Does GSM vary between deliveries?
Ask your supplier what variation they allow from the stated GSM, record the figure on your specification sheet, and check each delivery with a weighed square.