In what units is the print quality of printers measured?

Resolution when printing on laser and inkjet printers

units, print, quality, printers

For printing photos or small texts, at home, inkjet printers are best suited. Laser printers are used to ensure large volumes of printing requiring professional requirements for texts and printed images. These printing methods differ in many respects: technology, print speed, network media used and, of course, print resolution.

With polymer or gelatinous coating

Consumables used in printers:

  • laser devices use toner cartridges, one in monochrome and up to 4 in full color;
  • inkjet devices use ink cartridges, a separate black cartridge and a color cartridge, which can be combined or separate according to the primary colors.

Measuring Resolution in Printers

As already mentioned, resolution is determined by the number of dots plotted per 1 in². dpi (dots per inch). The amount of resolution is calculated from the horizontal and vertical components. Most often, the dimensions vertically and horizontally coincide. with a resolution of 300 dpi, 300 × 300 pixels are placed on 1 in², that is, 90,000. But sometimes they also use different resolutions in height and length. 600 × 1200 dpi, in this case on 1 in² will have 720 thousand points. 600 points will be plotted along the height of the square, and 1200 along the length, this is achieved due to the parameters of the point itself.

A computer monitor also transmits an image with a specific resolution, the size of which is measured in pixels. The color quality indicators of the monitor are much lower than that of the printer. For comparison, a drawing on a computer screen with 800 × 600 pixels, after converting it to print, will show only 50-80 dpi. The printer with the lowest resolution will print the image at a higher quality level.

KYOCERA multi-bit technology

Ways to increase the resolution

The main method is the use of nozzles in the print head of an inkjet printer, emitting droplets of various sizes. Laser printers accordingly use the smallest particle size toner.

The first, the technology with different-sized points, was applied by Hewlett-Packard. Small dots are located around large dots and, by mixing dot prints of drops of different sizes, it was possible to achieve smoothing of the teeth and increase color rendition.

How dpi is measured

Laser printer and its print resolution

Looking to buy a laser printer or MFP, or looking for a printer that does laser printing? Remember one thing: the law we deduced “more dots. better image” is useless here. Since it is powerless in the case of laser technology, that is, with printers and MFPs. They are carriers of the multi-bit method of full color printing, that is, they produce objects comparable to products of devices with high print resolution. Let’s discuss in more detail.

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As we said, any picture is formed from pixels, while the latter are formed by points according to the principle: on or off, that is, there is a point or it is not. In the first case, one of the four existing color channels is used: cyan, red (magenta), yellow (yellow) and black (black). Let us clarify that points from one channel completely coincide.

In this regard, the term “equivalent to 9600 dpi” is traditionally used. It allows you to determine the level of products with a printer print resolution of 600×600 dpi using the multi-bit method. The advantage of this method is that it makes it possible to produce high-quality colored materials, keeping the number of vertically arranged dots in one inch and the time spent during the operation of the equipment.

Take a look at the two examples provided. Immediately you can see: the left text, reproduced by a printer with multi-bit technology, is much clearer than a picture from a comparable machine with a print resolution for a 600×600 dots printer. Note that it is not inferior to an image made by a machine with an index of 1200×1200 pixels.

Let us add that the difference in the quality of reproduction between a printer with a resolution of 1200×1200 dpi and a device with a resolution of 600×600 dpi from the same manufacturer is quite insignificant. This is due to the peculiarities of the structure of the human eye: at a distance of 25 centimeters from an object, we cannot distinguish such small objects as points located at a distance of 0.04 mm from each other. Therefore, the human eye does not recognize the difference between the print resolution for a 600×600 printer and a resolution of 1200×1200 dots. In the first case, the distance between the points slightly exceeds 0.04 mm, and in the next version it is in our range of perception.

Let’s conclude: it is very important to remember that a large number of dots per inch is not always able to provide a significantly higher level of a printed product.

Print resolution: how well your printer can print

Need to print an ad, poster or photo calendar? And you are not sure if your printing device will cope with this task perfectly? Then it’s worth understanding the concept of print resolution. Printer resolution refers to the maximum number of dots per square inch that a printer can print in a given number of passes of the print head.

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The term “resolution” itself is used to describe the quality and contrast of a print. This indicator directly depends on the number and size of points. This also affects print quality.

If you look at an image printed at low resolution, you can easily notice graininess. That is, the points that form the image are clearly visible. This effect is caused by the fact that these points are quite large and exactly the same size.

For comparison, you can look at an image printed on a high-resolution printer. Here the picture will be solid. In this case, the dots are much smaller, moreover, they have different sizes.

Resolution is measured in units of “dots per inch”. dpi (dots per inch). For most printing devices, the print resolution is determined by the vertical and horizontal directions. That is, a resolution of 300 dpi means 300×300 dots per square inch. That is, a device with a resolution of 300 dpi can print 90 thousand dots per square inch of paper.

There are printers that have different vertical and horizontal resolutions (600×1200 dpi). In this case, the printer can print 720 thousand dots per square inch.

The resolution of your printer and your computer monitor should not be confused. The monitor resolution is understood as the number of pixels, let’s say 800×600. If you convert this amount to a print standard, you get about 50-80 dpi. Even a printer with the lowest print resolution will produce an image with many more dots than is displayed on your computer monitor.

For photo printing, 90k dots per square inch may not be enough. When printing text files with this resolution, characters may appear with a “jagged” effect. In this case, it is wise to increase the print resolution. The indicator of most modern inkjet printers is 5760×1440 or 4800×1200 dpi. Such devices will produce prints in higher quality and without graininess.

Image quality can be improved by changing the pixel size. This will not increase the resolution. This method was proposed by Hewlett-Packard. With this technique, small dots are placed in “corners” that form large dots. By mixing points of different diameters, it is easy to achieve smoothing of the “jagged” effect.

A large print resolution requires an impressive amount of memory. Some manufacturers increase the resolution without changing the amount of built-in memory. Such a device will be able to process a file with a resolution of 600 dpi, and then interpolate it to 1200 dpi. This image looks much better after interpolation, but a “true resolution” printer will print much better.

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Which resolution should be used for different printing tasks?

For a richer and more vivid image, you can use high-pass printing.

The number of passes affects the saturation of the print. Everything is simple here. The more passes, the brighter the colors. The essence of such an overprint is that the printing device “draws” the same area in several passes. This spills out more ink than usual.

This method is applicable for printing on translucent films, which are used “through”. It can also be used if you need to make the print more saturated.

When you need to create a banner, photo portrait or poster, the question often arises of what resolution to print it. Let’s give a couple of examples for clarity.

For billboards and advertising stands of large sizes, which will be viewed from a distance, use a resolution of 360 by 360 dpi. In such cases, the grain in the image will not be noticeable. It is impractical to use high resolution here, because the price of a print in this case will be colossal.

If the image will be viewed from a distance of about 50 centimeters (a regular photograph, for example), then it is better to use a resolution of 720 by 720 dpi. Small details with such printing will be more clearly traced, and the image will look uniform. Here, the cost will be slightly higher than in the previous version.

For high-quality interior printing, a resolution of 5760 x 1440dpi should be used. Such images will look great from any distance. The colors will be rich and vivid. Printing costs will be high.

From all of the above, we can conclude that if you need to print photographic quality, you should choose a printing device with a high resolution (5760 x 1440 and more). This can be, for example, an Epson XP-620 (if you need a multifunctional device) or an Epson 1500W printer.

If your advertising posters will be viewed from a distance of 50 centimeters or more, then printing from 360 to 720 dpi is suitable for you.