Printing is as much an art as it is a science. Clear, crisp images help enhance the look of whatever it is we are printing, and is every bit as important as the accuracy of the information that we might present alongside it. In the world of thermal printing, we might be printing shipping labels using a chemically treated paper, or nutrition labels for food packaging, or plastic pot stakes for plants at a nursery, or very tiny labels that are affixed to electronic parts, or large drum labels for hazardous materials. Any of these tasks and many others we might think of require us to think about the kinds of surfaces on which we are printing and what sort of ribbons we may need to create the final product.
Once we have settled on the right materials, we have to do the actual label designing and printing, and it is here that we can do a few very simple things to optimize the quality of our work. Here are five ideas that may be helpful.
1. Take It Slow
Thermal printers are capable of running from 2 inches per second (ips) up to 16 ips, depending on the model. However, as a general rule print quality is much more precise at slower speeds. Small fonts and bar codes especially tend to be sharper and cleaner at 2 or 3 ips than at higher speeds. The fact is that the faster the printer runs, the faster the print head dot rows have to turn on and off. The residual heat from these dot rows can easily cause smudging of small fonts or leave trailing edges on larger images and bar codes. The result then can be sloppy looking texts and bar codes that may not scan correctly, or worse, may be wholly unreadable. While speedy printing might be desirable, a more relaxed pace is apt to produce a higher quality outcome.
2. Use Less Heat
One effect of increasing the print temperature is, not unexpectedly, an increase in the darkness of an image. But, as the darkness increases, so does the size of the object being printed. Fonts printed at a very high temperature look somewhat bulkier and more filled in or run together than those printed at a lower temperature. Similarly bar codes look heavier or even sometimes distorted a bit, even to the point that the bar width ratios are affected, thus reducing the readability of the code. The issue here is really a matter of relative heat, because different print applications will of necessity require different heat settings. The key is to choose the lowest temperature that produces a clear and accurate image.
3. Keep Pressure to a Minimum
Some of the printers that use a so-called ‘flat’ print head also have one or more devices on top of the head to control the amount of downward pressure exerted upon it. Typically increasing the pressure will affect the relative darkness of the printing, and may also affect the overall evenness of printing across the width of the head. Because these effects are similar in character to those for heat, it is best to choose the lowest pressure setting that permits clear, even printing across the head.
4. Let Your Software Run the Printer
Label design software programs are perfect for designing all sorts of formats, and include an array of features to control the look of texts, bar codes, and graphic images. Because elements such as speed and temperature may vary significantly among different label designs, it makes sense to let your software program control these factors, as well as others. By creating a label design and saving your customized settings with it, you will be able to call up those settings every time you want to print, and so not have to worry about whether you have the right settings on the printer. Instead, the printer will simply take the commands that come from your software and reproduce your label just as you designed it.
5. Experiment with Graphics Settings
Although the graphics tab of Windows thermal printer drivers can seem a little scary, there are options here that can be useful at times. The available settings, which have fancy names such as halftone, algebraic, or error diffusion, are simply alternate ways of changing the appearance of a graphic image. For example, you might find that when you import a jpg into your label format, it looks splotchy and uneven. To smooth it out, you might choose ‘error diffusion’ to give it a more photographic quality. You’ll find that some images work better than others, and some you may decide you should just get rid of, but the point is that you should not be afraid to experiment with these settings if you need them.