What Does the Weight of Paper Mean?

So you’ve just installed your new cartridges and you are getting ready to print your latest family photos/excel spreadsheet etc. But have you thought about what paper you are about to print on to?

For the home user, the type of paper to print on is often one of the least thought about areas of printing – but can make a huge difference in quality and cost. However there are more than a few printer paper options available to you. In this article we will quickly look at the most common options available to you.

Types of Paper

Most types of printer paper can broadly be split into two categories: coated and uncoated.

– Coated

Coated has a very thin coating on the surface. Coated papers are typically made by applying a fine layer of an calcium carbonate or china clay to the surface of an uncoated sheet during manufacture. This coating may be performed more than once depending on how smooth a finished surface is required by the manufacturer. In addition the paper will usually also be “milled” smooth between hard rollers at the end of the process, as this will help increase the paper sheet’s smoothness.

An additional treatment may be applied too, for instance if the paper needs to be silk or gloss for photograph paper.

The Most Common Coated Paper Types Are:

Glossy – The most common type of photo paper, it has a glossy coat usually only on one side that has a more reflective finish than other paper types, but because of the reflectiveness it can cause glare. The glossy coating stops ink soaking into the paper so it sits on top and gives sharp/vibrant colours. (You can purchase Gloss paper designed specifically for either Inkjet and Laser printers).

Matte – Does not have a reflective coat like gloss so when printed on so the ink penetrates into the paper and appears duller, the upside of this means it doesn’t give of any glare.

Semi gloss or Satin – A mix and compromise of matte and glossy, has a sheen to it but not as much glare as glossy and not as dull as matte.

In general the more coating added to a sheet generally means more smoothness, which generally means it will hold the detail and colour better.

NB – It is also worth pointing out that adding a coating to a sheet changes the nature of the paper in a number of ways. The most common is that it can effect the “thickness” of a sheet or paper. For example, an uncoated 160gsm will be quite a stiff sheet of paper, but a 160gsm triple coated silk paper will thinner by comparison, although both are the same weight. This is because more of the weight of the silk paper will be taken up by the coating, which adds surface weight but not thickness to the sheet.

– Uncoated

Uncoated paper as the name gives away is standard paper without a coating, it is standard unfinished paper that you might use for printing letters. Different types of uncoated paper generally have the same finish but with different weights and quality (more on this later). Uncoated paper is normally called a number of other names depending on the quality such as inkjet paper, copier paper, economy paper, office paper or even just printer paper.

Specialist Paper Technologies

Many of the major printer manufacturers have invested in developing specialist paper to work alongside their inks and toners.

For instance:

Canon has developed a paper for professional and advanced amateur photographers called “Photo Paper Pro Platinum” it is six layer paper structure that they claim is used to promote vibrant color reproduction via quicker ink absorbency.

HP has its ColorLok Technology. ColorLok is an additive used during the paper making process that causes ink to adhere more completely to the surface of the paper. The following is a video watch Thom Brown – HP Supplies Technology Specialist talk about ColorLok

There are also other specialist mediums to print onto such as:

• Transparencies
• Stickers and Labels
• UV Gloss
• Rough Wood Pulp
• Recycled Paper
• Iron on Transfers

…you will need to check if your printer supports these media types.

Paper Sizes

Paper sizes are based on a globally recognised standard called the ISO 216 paper sizes. All ISO 216 paper sizes have the same aspect ratio of:

This ratio has the unique property that when cut or folded in half width wise, the halves also have the same aspect ratio. Each ISO paper size is one half of the area of the next size up. So, as an example, if you take an A3 sheet of paper and fold it in half, you will have the size of an A4 sheet of paper.

A4 is by far the most common paper size today which measures 210mm by 297mm, this is the size of most business letters used in the UK. In the ISO 216 standard – paper sizes are: A0, A1, A2, A3, A5, A6, A7 & A8 – as seen in the following diagram:

Most home and small business printers will not take paper sheets any larger than A4 paper, however you can purchase specialist printers that do take the larger sizes. One example is the HP 7500A Officejet Wide Format printer which will print, scan and copy up to A3.

HP Officejet 7500A A3 Printer

– Photo Paper

When it comes to the size of Photo paper for your inkjet printer, you will often see non ISO 216 paper sizes being used.

For instance:

AGFA market a pack of Photo Premium Glossy Paper but the size is 10 cm x 15 cm.

HP market a pack of HP Advanced Glossy Photo Paper but the size is 13 x 18 cm.

However, all the major manufacturers also provide standard A4 inkjet paper, with some (notably HP) providing A3 photo paper too.

…click here to see our range of inkjet photo paper.

Weights of Paper

The final part of this article looks at the weight of paper.

Paper weight, under ISO 216, is calculated in grams per square meter (g/m2). This is often abbreviated to just “gsm”.

Common weights are as follows:

75gsm – Thin and lower quality “copier” paper
80gsm – Typical office printer and copier paper
90gsm – A higher quality printer paper
100gsm – A very good quality office paper
120gsm – A very high quality office paper
150gsm – Used more in printing fliers as not “see through”
200+ gsm – Photo paper or thick paper not suitable for folding
300gsm – Thick card stock mainly used in business cards

Please check with your printer handbook as to the maximum size your specific printer can take, do not assume it will be able to take a 300gsm card stock.

You Might Also Like To Read:

Introducing HP ePrint
Inkjet or Laser Printing: Which is More Cost Effective?
Printing With Fire Instead Of Ink
Ink Cartridges: Original, Compatible or Recycled?
HP PageWide Technology
Printer Maintenance Tips