What Does gsm Mean? A Paper Weight Guide Without the Guesswork
You are ordering a leaflet, and the options ask you to choose a paper weight. Is 170gsm twice as thick as 85gsm? Will a heavier sheet make the design look better? Can your home printer handle it?
The number is useful, but it does not answer all those questions.
Gsm means grams per square metre. It describes how much a square metre of the paper weighs. It does not directly describe thickness, stiffness or surface finish. Understanding that difference makes choosing paper much less of a guessing game.
Weight is one measurement, not the whole specification
Imagine a sheet measuring one metre by one metre. If it weighs 120 grams, its grammage is 120gsm.
Your A4 sheet is much smaller than that, but it has the same grammage. Changing the sheet size changes the weight of the individual sheet, not its gsm.
Within a particular paper range, a higher gsm will often mean a thicker sheet. Across different papers, that relationship is less reliable. Fibre, coatings and manufacturing affect the result. Two stocks with the same gsm can feel noticeably different.
That is why asking for "the thickest 300gsm" is not a complete specification. You also need to know what the paper is and what the finished piece must do.
Thickness and stiffness are different again
Thickness is measured separately, often in microns. Stiffness describes how the sheet resists bending. Surface finish affects how it looks and feels.
A card can feel substantial because of its stiffness, even when another stock of the same grammage is thicker. An uncoated sheet and a coated sheet may show photographs, writing and texture differently.
Do not judge all of those properties from a weight label. If the feel matters, compare samples. If you are posting, folding or putting the print into a holder, check the actual finished construction too.
A quick comparison chart to print and keep
These are broad starting points, not product specifications or promises that every printer stocks every weight.
Weight range | A common starting use | What to check |
80-100gsm | Everyday documents and economical inserts | Show-through, writing and double-sided readability |
120-170gsm | Leaflets and lighter brochure pages | Fold, opacity and the feel of the specific stock |
200-250gsm | Heavier covers, cards or sturdier leaflets | Whether it needs scoring and suits the print process |
300-350gsm | Business cards and substantial invitations | Actual stiffness, thickness and finishing suitability |
Print this article or copy the chart onto one sheet for reference. It is a decision aid, not a substitute for handling the paper. A separately designed comparison download is not yet available.
The uses overlap on purpose. A design, its intended use and the chosen stock may point to a different answer.
Match the paper to the job
For a leaflet, think about handling, folding and quantity. For a brochure, consider the page count and binding as well as the cover. A heavy sheet repeated across many pages can make a booklet bulky.
For an invitation or card, decide whether the piece needs to be written on and how it will be sent. The envelope and finished package matter too.
For a menu, consider frequency of handling and how often the information changes. A costly durable construction may be poor value if the prices need changing next month.
There is no universal "professional" gsm. The professional choice is the one that fits the purpose.
Check your home printer before choosing card
A paper being sold as printable does not mean it will work in every home printer.
Look up your model's supported media, weight limits and feed instructions. Check whether the sheet is intended for inkjet, laser or both. Use the relevant paper setting and make a test before feeding a batch.
Do not force unsupported card through a machine or assume a rear feed solves every limitation. The manual, not the marketing photograph, sets the boundary.
Ask a better paper question
Instead of asking, "What gsm looks expensive?", say what the piece needs to do.
"This leaflet will be folded and handed out outdoors." "Guests will write on this card." "This brochure needs to be kept and opened repeatedly."
Those descriptions help a printer recommend the paper, finish and construction together. Ask to compare suitable samples, then check the design on the chosen stock where practical.
Gsm is a good place to begin. The paper in your hand, and the job you need it to do, should have the final say.
Get in touch
If you have a question about your next job, visit our shop on Glasnevin Avenue, Glasnevin, email hello@printready.ie, or call (01) 858 1000.
