When printing on both sides of a sheet of paper a slightly higher paper weight will have the best results. In my experience 24-32 lbs is an ideal weight for two sided printing.
The reason you’d want to use a heavier paper is to prevent the text or image showing through. In most cases people printing B&W text two sided on plain 20 lbs paper just ignore the text showing through.
While too thin paper lets the ink and toner show through. You don’t want to use too thick of paper either. It makes the paper too stiff to duplex. In my experience 60 lbs is too heavy for two sided with most printers.
Paper Weights
Paper weights are in the USA are determined by the weight of 500 sheets of paper. Standard copy paper is 8½ x 11 inches and 500 sheets weigh 20lbs. So we call it 20lbs Letter size or plain paper.
Since weight is based on the manufacturers dimensions, different types of paper are measured by different sizes. Meaning, bond and index paper don’t use the same size when measuring 500 sheets of paper.
For example some Index papers have a lighter weight but are thicker than cover papers. Since 500 sheets of 22.5 x 28.5 paper is going to weigh more than 500 sheets of 20 x 26 inch paper. So weight doesn’t accurately reflect thickness.
As long as similar sizes and types are being compared, paper weights generally correlate to a paper’s thickness and stiffness. When different sizes and types of paper are being compared thickness is not always accurately reflected by weight.
In my experience grams per square meter (GSM) is a more accurate measurement of a papers thickness. GSM is based on a square meter instead of a paper’s varying dimensions. It’s a universal measurement for paper weight.
While GSM is more accurate, pounds are more commonly used in the USA. I’ve found you really have to search a printers documentation to find specs for GSM. Also, most paper sold in the USA is advertised in pounds while GSM isn’t always listed.
If you want to know how thick a paper is go by it’s GSM, not pounds.
Summary
A paper’s weight in the good ol’ USA is based on it’s size. The weight of 500 sheets of paper does not always reflect it’s thickness.
GSM is a universal measurement of a paper’s weight and more accurately reflects it’s thickness.
When printing two sided pages you don’t want to use paper that’s too thin or too thick. Too thin paper will show through whereas too thick paper will jam.
If you’re printing on both sides of a page then use a heavier weight of paper to prevent the other side showing through.
FAQ
24 -32 lbs paper is ideal for 2 sided printing.
You can print double sided on 20 lbs paper. However, text and images on the other side will show through.
You can print double sided on any size paper supported by your printer. Printers can duplex Letter, legal, statement or tabloid.
If it’s the same type of paper the higher the weight the thicker the paper. When comparing different paper types, weight is not necessarily a measure of thickness. Different tree fibers are used in various paper types. Therefore denser fibers can lead to a heavier weight but thinner paper.
The Copier Guy, aka Dave. I’ve worked on scanners, printers, copiers, and faxes since 1994. When I’m not fixing them I’m writing about them. Although, I’m probably better at fixing them. I’ve worked with every major brand. As well as several types of processes. If it uses paper I’ve probably worked on one.
