Illustrator Dpi | Illustrator – Calculate File Dimensions And Resolution For Accurate Output

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Helen Bradley

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Illustrator - Calculate File Dimensions And Resolution For Accurate Output

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Hello, and welcome to this video tutorial today. We’re looking at how you can get from Adobe Illustrator, a file at the right physical pixel dimensions and the resolution that you want, it’s not as easy as it looks, but I’ve got a foolproof way of doing it before we begin. However, I have more Illustrator training at Skillshare Com. When you sign up for Skillshare, you get access to thousands of classes there, including over 250 of mine in the description below, is a skill share coupon for you, which it’s at least as good as the current skill share offer and typically, mine will be better. I also have Illustrator training at Udemy Comm and there’s a referral link for each of these courses in the description below, Please feel free to share these with family, friends and co-workers. Let’s return to illustrator and let’s have a look at the issue. The problem is creating a document in Illustrator that you want to save out of illustrator, as for example, a JPEG file to predetermine how big it’s going to be on export. So I’m going to take scrapbook paper as my example, because it’s pretty easy and a lot of people do it. A state of scrapbook paper is 3600 by 3600 pixels in size and it’s typically distributed at 300 PPI or DPI. It doesn’t matter. What terminology you use? But it’s the 300 is the resolution, So here’s the issue. If you go ahead and create a document that is 3600 by 3600 pixels in size, It’s not going to work. Let’s just have a look at the issue, so I’m making a document 3600 by 3600 pixels in size. This resolution value here is only for raster effects. It has no impact on the final image size. So just ignore that for now. That’s not what we’re looking at. I’ll click create. So this is my 3600 by 3600 pixel document. I’m going to add a rectangle to it. I’ll just square it up on the artboard and I’m going to fill it with a color now. We’re going to save this and we’re going to save it using the method in Illustrator that allows you to specify the output resolution, so we’ll choose file and then export and export as Ill type a name for this. I’m going to select use our odds because I want to export that artboard. I’ll click export now. I can choose the quality and I’m going to do a lower quality now. This slider here has to do with the quality of the file. It has nothing to do with their physical dimensions. The width and height here is the resolution. I’m choosing 300 PPI because that’s what scrapbook paper uses. I’ll click, OK? Now, saving this document, which we set up at 3600 pixels by 3600 pixels. And we said, save it at 300 PPI, it’s not unreasonable, perhaps to expect that that’s what we’re going to get at the other end, a document that’s 3600 by 3600 at 300 PPI, it’s just not the case. I’ve opened up the folder that that file was saved to lets. Just click it. Let’s go to the pink square. Let’s read the dimensions off down here. The dimensions are an enormous 15,000 by 15,000 It just hasn’t worked, but if I right-click this image and go to properties and check the properties, you’ll see that the PPI or the DPI is correct. It’s 300 it’s just the file sizes blown out too unreasonable and totally unexpected dimensions. Well, it is sort of unexpected. If you don’t know what’s going on, so here’s a story the way that illustrator works is that whatever you create in Illustrator, it assumes it’s going to be at 72 pixels per inch, so let’s have a look at the mathematics of this. We just created a document that was 3600 by 3600 so let’s just type that in here. And if Illustrator assumes that that’s going to be at 72 pixels per inch, let’s divide it by that 72 pixels per inch, and that’s the number of inches wide that illustrator thinks this document is going to be so when it creates a 50 inch document at 300 PPI, let’s multiply by that 300 PPI and see what we get. Not surprisingly, there’s where the 15,000 came from. So that’s why it happens, but let’s have a look and see how we can avoid this happening to us, so let’s say that we want a document that is 3600 by 3600 pixels in size. Well, we’re going to type in 3600 here because we’re going to test it, and then it needs to be at 300 DPI, so I’m going to divide by that 300 value, and that gives me 12 12 inches illustrator works at 72 PPI, So let’s multiply it by 72 This is the size of the document that we need eight hundred and sixty-four pixels if we create a document 864 by 864 and then save it exactly the way that we did at 300 DPI we’re going to get a 3600 by 3600 pixel image as confusing as that might be. It’s going to work. Let’s go and see it in practice file new. I’m going to choose one. That’s 864 by 864 again. This raster effects has got nothing to do with what we’re talking about here. I’ll click create. I’ll add a rectangle into this. That’s 864 by 864 I’ll fill it with a different color. This time, we’ll go for green, having created it. We’ll go and save that file export export as I’ll choose use artboard’s click export quality can be whatever I need. It’s not going to have any effect on the physical dimensions of the file, the width and the height. I’m setting it to 300 PPI because that’s what we made our calculations on. Ill click. OK, lets. Go back to the folder. Click on the file. Now we have a file. It is 3600 by 3600 pixels in size, When I right-click it and choose properties and check out the resolution, you’ll see 3600 by 3600 at 300 DPI, So we’ve managed to create the document that we wanted in Illustrator, so that all begs the question as to. How do you make the calculations of a physical size of a file that you wanted a certain resin? Lucien, when you’re working with illustrator? Well, this is how you’re going to do it. You’re going to take the physical dimensions, the number of pixels wide and tall, and in each case, you’re going to divide that by your output resolution. If you’re using 300 DPI, divide it by 300 if you’re using 150 divide it by 100 and 50 and whatever value you get there, just go ahead and multiply that by 72 so divided by your resolution multiplied by 72 and that will give you the pixel dimensions that you want for the image you’re creating so for arguments sake. If we want a document, that’s 600 by 300 at 300 DPI, 600 divided by 300 is to multiply 2 by 72 That’s 144 It needs to be 144 wide and 72 tall. If you do that output, it at 300 dpi. You can have a perfect result. This is confusing stuff. I really hope that I’ve been able to help you make calculations of file sizes in Illustrator so that you can output direct from illustrator and use the JPEG files without having to take them to Photoshop to adjust the resolution. If you enjoy the video, give it a thumbs up, hit the subscribe button and that notification bill, so you’ll be alerted when new videos are released until next time. I’m Helen Bradley. Thank you so much for joining me here on my Youtube channel.