Print Image Quality Requirements For Graphic Art Industry

After reading the title, many questions pop up in your mind like Is image quality affects prints? How it is connected with graphic industry? How one should decide which requirements are needed to print a good quality? By which factors image print quality will decide? Does it really necessary to think of image quality while printing? And so many other questions. So wait, don’t worry at all. By the end of this article you will get all answers of your queries. The title itself indicates that how we will improve print quality by studying image quality requirements for graphic art industry.

Does image quality affect prints? Yes of course it affects print quality. When sending a graphic design to print, there are various image quality attributes like Tone reproduction, Sharpness, Image noise and distortion, lightness, Image size, Contrast. Also, there are some factors which one should check before printing of course on the computer only. Factors like Dot shape, LPI, DPI, Resolution, Colour are important to look upon so that image quality will improve.

Colour is nothing but light means when light is reflected off an object, what we see from eyes is colour. Colour has three properties that are Hue, value, Intensity. Hue, in the context of colour and graphics, refers to the attribute of a visible light due to which it is differentiated from or similar to the primary colours: red, green and blue. Hue is also used to refer to colours that have no added tint or any shade. Value is defined as element of art associated with the darkness or lightness of a colour. Chroma is nothing but strength or intensity of a colour. A high Chroma colour is pure from any presence of gray or white. For example, lemon yellow has a high Chroma, while a banana yellow has lower Chroma. Colours with strong Chroma are often referred to as bright or saturated; however, the term brightness is also used to describe the intensity of light and, therefore, indicates a combination of value (lightness) and Chroma.

Colour perceptions can only be described clearly means by comparisons and by contrasts. For example, an identical neutral gray tone field appears greenish on a red background and rather red-dish on a green background as shown in fig. This effect is known as simultaneous contrast.

Fig 1. Simultaneous contrast

So from this image we can conclude that surrounding conditions are affecting the contrast. Sharpness is another attribute of image quality which affects the print. So what do you mean by sharpness? It describes degree of clarity of the edges of that image. Too much sharpening can diminish image quality.

Fig 2. Sharpness

Halftone screens are measured in lines per inch (LPI), which is equivalent to the number of halftone dots per linear inch. LPI is a measure of how close together the lines in a halftone grid are. The quality of printer device or screen determines how high the LPI will be. High LPI indicates greater detail and sharpness. Dots-per-inch (DPI) it generally used to describe printer resolution and often used to describe scanner resolution. Obviously the higher the number the better the resolution of the image.

Fig 3. Different LPI

So from fig 3. We can say that higher dpi will get higher quality as good quality occurs in higher DPI.

Image Resolution is one of the important factors that affect the print quality. Image Resolution controls the quality of the printed image. Well, let me throw one more thing in there that image resolution has nothing to do with, and that's how your image looks on your computer screen. That's right; the resolution of your image has absolutely nothing to do with how your image appears on screen. It does, however, have everything to do with how your image will print. The printed quality difference between the high and low resolution seems clear to the naked eye as shows in the fig.

Figure 4:- Resolution

Resolution is nothing but pixel size. There's one other aspect that image resolution has to do with, and that's the size of the pixels when you go to print the image. It makes sense, really. An inch is an inch is an inch. The size of an inch is always the same. It's, well, one inch. So, since the size of an inch can't change, the size of the pixels has to change. For example, in order to fit 300 pixels into an inch, you would need pixels that are considerably smaller than if you only wanted to fit 72 pixels into an inch. Fortunately, you don't need to worry about that. Photoshop takes care of resizing the pixels for us. I just want to explain that "image resolution" really means two things - the number of pixels per inch that will be printed on the paper and the size of those pixels. As I said, though, Photoshop takes care of sizing them for us. All we need to do is make sure we're using the correct value for "pixels per inch".

Does Dot shape affect print quality? Yes, it can affect print quality. Dot shape is nothing but the geometric appearance of a halftone dot, which may vary from elliptical to perfectly round to square. Depending on the application, the shape of halftone dots can be varied to eliminate such problems like moiré and dot gain.

Do you wander after knowing, surroundings condition is also important for image quality as the change of surround conditions affected the colour appearance? Also customer’s preference for colour images and more objective image quality attributes matters. You may think why customer’s perception is important. So I want to clear you that yes of course it is important because after all, your product or anything which have printed image on it, it should attract the customers so that you will get benefit from it and your product should have more sales and better value in the market.

So yes, all of these attributes, some factors and terms are very important and they matter a lot for getting good quality print. I hope I cleared all the necessary points and solved your queries. Thank you.

Ms. Pranali P. Katariya

TE Printing

PVG COET & GKPWIM

References-

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