One of the most common types of impact printers is called a dot matrix printer. This is because it creates an output on the page by using a small matrix of pins, pressing those pins against a ribbon, and eventually making a mark on the paper. And if you look very carefully at the characters that are printed on the page, you'll see that they are made up of very small dots. Those little tiny dots are the pins inside of the dot matrix print head. Since these pins are pushing on the paper itself, it's perfect to use for carbon copies or multiple copies where pushing on one page will create more copies of that page behind it. This is also a relatively low cost per page. So, if you're printing a lot of output, you may be able to save money by using a dot matrix printer. But unfortunately, these are relatively noisy printers. So, if you're working in a library or somewhere where it's very quiet, this might not be the right printer to use. And as you can see from the characters that are printed on this page, this is a very poor printer to use if you're trying to create any highresolution output. This is why we rarely find dot matrix printers in our homes and our businesses these days and instead it is used in very niche cases where the best possible printer for that particular use would be something like a dot matrix printer. This printer head moves back and forth across the page. There are small pins inside the print head. The small pins are inside the very front of that print head. it is pushing those pins into the ribbon where the ink is and that ink is being transferred to the paper that's behind it. If we were to look at the print head, it's relatively small and you can see there's a pretty large heat sink on the back of it because these print heads do get relatively warm. But it is a single print matrix. So to be able to print on an entire page, we would have to move that print matrix back and forth across the page and then move the page up to print the next line. Here's a better view of this dot matrix printer in use. You can see the print head moving back and forth across the paper and you can see the page is moving underneath the print head to be able to print on other parts of the page. If we were to remove the print head from the printer and look at the print head itself, you could see that is relatively small. This is the matrix of pins that are on the print head and that is what is making connection with the ribbon and ultimately with the page behind it. The printer ribbon itself is usually one cartridge that fits inside of the printer. And the ribbon usually stretches all the way across the page, making it easier for that print head to move back and forth to make the output. This is a single unending ribbon, so it will cycle all the way through this printer ribbon case, come out the other side, and keep going over and over again until you replace the entire cartridge. Fortunately, it's relatively easy to replace these cartridges. They pop right out of the printer. you can put a new one in place and usually that exchange only takes a few seconds. Different makes and models of dot matrix printers tend to use different sizes of printer ribbons. So when you're replacing this ribbon, you want to be sure to get the right ribbon for the make and model of printer that you're using. If we were to pop open the top of that printer ribbon, you would see that it is one long piece inside and it usually collapses into itself in that repository area until it's ready to come out and make contact with the page. Not only do we have this ribbon that is moving as the print head is going back and forth, but very often we're using a tractor feed to pull the paper through the printer itself. This is regular printer paper, but there are holes on the left and right side. Those holes line up with these tractor feeds that are connected to the printer and that pull the page into the printer so that we can move it past the print head. These holes have to line up perfectly on each side so that the page is straight. If you miss one of these holes when you're trying to add more paper or you happen to misalign it as it's going into the printer, then you're probably going to end up with a paper jam. We often refer to this paper as tractor paper because it has these tractor feed holes on the left and right side. This might be one long continuous piece of paper or it may be perforated so that you can have standard size paper once it goes through the printer. Many of these tractor feed pages also have perforation so that you can remove those little tractor feed holes on the left and right side and end up with a page that looks relatively normal when you're finished. And in some IT environments, you might still be using green bar paper like the one we have here. This is commonly used on dot matrix printers. You can see the tractor feeds on the left and right side. and it was commonly used to output source code so that programmers could work on their output on something that was printed. One common use of dot matrix printers is to use a multi-art paper. This means that we can have one pass through the printer and have multiple copies that we printed using that impact printer. We traditionally used carbon or carbon paper to be able to create that additional copy. But a less expensive and easier to manage process uses microenccapsulated ink on the back of that very first sheet. This uses clay on the second sheet that has a reaction to that ink to create that additional copy underneath. This creates that copy on the second page without us physically touching the second page itself. This combination of inks and dyes with the clay that's on the paper can create irritants in some people. So, you may find that after you use these multi-art papers over a period of time that you may have some irritation to the skin. Many organizations have found it easier to simply print another copy instead of having this multi-art paper with an impact printer. Ultimately, it might be less expensive and easier to manage than all of these moving parts inside of a dot matrix printer. And as the popularity of dot matrix printers is fading away, you may find it easier and much more convenient to use a different type of printer.