A school project needs a cover page that looks a little more finished than the worksheets behind it. A parent reaches for the same 80gsm ream used for everything else, prints it, and the page feels thin next to the printed cover of a commercially produced handout. This is the moment 100gsm earns a place in the paper drawer, even if it never becomes the everyday choice.

This guide compares 80gsm and 100gsm copy paper directly, with a focus on when the heavier option is genuinely worth buying. It builds on our wider explanation of what GSM means on school paper and sits inside our notebooks and paper for school guide.

Quick answer

80gsm is the common weight for A4 copy paper in Australia and suits everyday school and home printing. 100gsm is heavier and can provide a more substantial feel and better opacity, which can help reduce show-through on colour-heavy or double-sided pages. For most everyday school printing, 80gsm is a practical choice. Choose 100gsm when a specific job benefits from greater opacity, presentation or handling strength rather than switching everything to the heavier weight. 

What Separates 80gsm From 100gsm

GSM stands for grams per square metre, the standard way paper weight is measured. An 80gsm sheet weighs 80 grams per square metre. A 100gsm sheet weighs 100 grams per square metre, roughly a quarter heavier.

That extra weight generally brings a few practical differences:

Key note: A higher GSM number is a reasonable general guide to thickness, but coating and fibre density can still make two papers at the same GSM feel slightly different. This is covered in more depth in our guide to what GSM means on paper.

Why 80gsm Is the Australian Default

80gsm is not an arbitrary choice in the Australian copy-paper market. Australian government records describe A4 copy paper as predominantly 80gsm, with smaller quantities sold at other weights such as 70gsm, 90gsm and 100gsm.

For everyday school and home printing, 80gsm offers a practical balance between paper weight, cost and general usability. It is widely available and suitable for worksheets, reading logs, homework and other routine documents.

For a student printing worksheets or general homework most weeks of the term, 80gsm remains the sensible starting point. Our ECOEARTH Recycled Copy Paper A4 80 GSM is a straightforward example, made from 100% recycled paper at the standard 80gsm weight.

When 100gsm Earns Its Place

100gsm is not simply a premium upgrade to apply everywhere. It solves specific problems that 80gsm sometimes cannot.

• Double-sided colour printing. Heavier paper can reduce the visibility of colour or dense text through the back of the page.
• A cover page or title page for a school project. The extra weight gives a more finished, deliberate feel without needing card stock.
• Documents that will be handled repeatedly, such as a certificate, a timetable pinned to a wall, or a reference sheet kept out on a desk.
• Printing where the paper itself needs to hold up to handling, more than a worksheet that is used once and filed away.

Key note: 100gsm is not necessary for most everyday school printing. Reserve it for the specific jobs above rather than switching the entire household or classroom supply, since the cost difference adds up quickly at high print volumes.

Show-Through, Opacity and Double-Sided Printing

Show-through is the main practical reason to consider 100gsm. Lighter paper has less fibre to block light and ink from the opposite side, so text or colour printed on one side becomes more visible through the back of the page.

This becomes noticeable in a few common situations:

• Printing a worksheet with a full-colour image on one side and text on the other.
• Double-sided printing of dense, text-heavy pages.
• Printing ink-heavy pages on some inkjet printers, where larger amounts of liquid ink can make show-through more noticeable on lighter paper.

For a single side of light text, 80gsm is usually sufficient. For full-page colour, dense graphics or heavier double-sided printing, 100gsm can reduce show-through and give the page a more substantial feel. Our guide on why 70gsm paper bleeds explains the mechanics of bleed-through and show-through in more detail.

Cost Per Page, Worked Simply

The cost gap between 80gsm and 100gsm is usually modest per page but becomes more noticeable across a full ream or a school term of printing.

A simple way to compare value is to check the price per 100 sheets or per ream, rather than comparing pack prices at a glance, since pack sizes vary between brands. Once you know the cost per sheet for each weight, the decision becomes practical rather than guesswork. If the extra cost of 100gsm is justified by the job, the heavier paper may offer better value for that specific use; otherwise, 80gsm keeps high-volume printing more economical. 

Key note: Buying a smaller supply of 100gsm alongside a larger, everyday stock of 80gsm is often more cost-effective than switching entirely to the heavier weight. Our guide to bulk copy paper quantities covers how to think about reams, boxes and larger quantities for regular printing needs.

This two-tier approach also suits how most households and classrooms actually print. The bulk of everyday printing, worksheets, reading logs, drafts and general notes, rarely benefits from the extra weight. Keeping a larger 80gsm supply covers that volume affordably, while a smaller, occasional stock of 100gsm sits ready for the handful of jobs each term that genuinely call for it. This avoids paying a premium across every page printed, while still having the right paper on hand when it matters.

Printer Compatibility Across Weights

Many home and school inkjet and laser printers can handle both 80gsm and 100gsm paper, but supported weights and recommended settings vary by model. Some printers may offer a heavier or premium paper setting that can improve feeding or print results when using thicker stock. Check your printer's manual for the recommended paper weight and settings before starting a large print job.

Very heavy paper, well above 100gsm, can sometimes require a manual feed tray or may exceed what a particular printer supports. Check your printer's manual if you plan to print anything heavier than 100gsm regularly. For 80gsm and 100gsm specifically, most standard printers handle either weight without special setup.

This is worth checking once, rather than assuming, especially for older printers or smaller home models that were designed with lighter everyday paper in mind. A quick test print on a single 100gsm sheet before committing to a full print job is a simple way to confirm your printer handles the heavier stock well, particularly if you are printing something that matters, such as a school certificate or a project that only gets printed once.

GSM and Paper Jams

A common assumption is that heavier paper causes more jams. Paper weight is only one factor that can affect feeding. Paper that is curled, poorly stored, incorrectly loaded or mixed with other paper types can also contribute to feeding problems.

Our guide on why your printer keeps jamming goes through these causes in detail, including simple habits that reduce jams regardless of which paper weight you use.

A Simple Decision Guide

Paper Options at School Stationery Supplies

The product below is available through our Notebooks & Paper collection. Confirm current stock and specifications before ordering.

If your household or classroom regularly needs a heavier weight for cover pages or presentation work, a smaller separate stock of 100gsm alongside your everyday 80gsm ream is the most cost-effective approach.

Common Mistakes When Choosing Paper Weight

• Switching everything to 100gsm "just in case." This adds unnecessary cost for printing that never needed the extra weight.
• Assuming 80gsm always causes show-through. For single-sided, light text printing, 80gsm performs well.
• Comparing pack price instead of price per sheet. This can make a smaller, cheaper-looking pack seem like better value when it isn't.
• Ignoring the printer's paper type setting. Selecting "heavy" or "premium" paper mode can improve results noticeably on 100gsm without buying a different printer.
• Blaming paper weight for jams that are really about storage or tray habits. Check the actual cause before assuming heavier paper is the problem.

Frequently Asked Questions

Is 100gsm better than 80gsm for school printing?

Not universally. 100gsm reduces show-through and feels more substantial, which suits cover pages and double-sided colour work. For everyday worksheets and general printing, 80gsm performs well and costs less.

Does 100gsm paper reduce printer jams?

Not directly. Jams are usually caused by storage, tray overfilling or mixing paper types, rather than the weight of the paper itself. Both 80gsm and 100gsm can jam if stored or loaded poorly.

What GSM is standard copy paper in Australia?

80gsm is the predominant weight for A4 copy paper in Australia, although other weights including 70gsm, 90gsm and 100gsm are also sold. Printer compatibility varies by model, so check the manufacturer's specifications for supported paper weights.

When should I use 100gsm instead of 80gsm?

Use 100gsm for double-sided colour printing, project cover pages, certificates, or any document that will be handled repeatedly and benefits from a more substantial feel.

Can I mix 80gsm and 100gsm paper in the same printer tray?

It is generally best to avoid mixing different paper weights in the same tray at once, since this can cause uneven feeding. Load one weight at a time.

Choosing the Right Weight for Each Job

80gsm remains the sensible everyday choice for most Australian school and home printing. 100gsm earns its place for specific jobs where show-through, presentation quality or repeated handling genuinely matter.

Keep a main supply of 80gsm on hand, and add a smaller stock of 100gsm for the jobs that benefit from it. Checking price per sheet rather than pack price, and testing your printer on a single heavier sheet before a big job, are both small habits that make the decision easier next time. For the full picture on notebooks, paper and quantities, see our notebooks and paper for school guide. Ready to stock up? Browse our Notebooks & Paper collection.

Supporting Articles in This Series

• Notebooks & Paper for School: The Complete Australian Buying Guide
• Dotted Thirds, 8mm, 14mm: Australian Exercise Book Rulings Explained
• A4 vs A5 Exercise Books: Which Size Does Your Child Actually Need?
• What Does GSM Mean on School Paper? (And Why 70gsm Bleeds)
• How Many Exercise Books Does a Student Need Per Year?
• Stapled vs Spiral vs Wiro-Bound: Which Notebook Binding Lasts a Year?
• How to Cover School Books Without Bubbles (Contact vs Slip-On)
• Recycled Notebooks and Copy Paper: Do They Hold Up in the Classroom?
• Ream, Box or Pallet? Bulk Copy Paper Quantities Explained
• Why Your Printer Keeps Jamming (It's Usually the Paper)

About the Author: 

The School Stationery Supplies Team publishes practical buying guides for Australian students, parents and teachers. Visit School Stationery Supplies for notebooks, paper, pens and school essentials.

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