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32

PPI (Pixels Per Inch) settings are not used in web images. Images on the web, retina displays or otherwise, are displayed by their pixel dimensions (width and height) not any PPI/DPI setting. In fact, many web images such as png, gif, jpg may not even store a ppi setting in their internal data and rely on width and height settings. A 100 pixel x 100 pixel ...


15

I've always thought DPI was somewhat of a misnomer... It really only applies if you are printing an image, otherwise, well, pixels are pixels. For an image on a site, well, it really doesn't matter, just get as many as possible, to fit the required size. Printers vary somewhat, but around 300 DPI is usually a good rule of thumb for anything around the size ...


12

The only definitive answer to this question is: Ask your vendor. Every vendor, every printer, every t-shirt maker, etc will have their own particular preferences as to how they want to receive files and how they want them set up. Discussing this with your vendor before you begin is crucial to ensure that the process goes smoothly. The general rules of ...


11

A pixel (the word was originally coined, iirc, by IBM and derives from "picture element") is the smallest indivisible unit of information in a digital image. Pixels may be displayed, or they may be printed, but you can't divide pixels into smaller pieces to get more information. How many channels and bits per channel make up one pixel is the measure of how ...


7

DPI (digital dots or pixels)/PPI defined: 300 dpi/ppi = 300 pixels used for every 1 inch line of ink coverage. 1000 pixels will yield a 3.3333 inch line @ 300 dpi of resolution DPI and PPI have been used interchangeably (though not always accurately) since pixels entered the printing industry. DPI comes from halftone/screen dots in offset printing. If a ...


7

If the printer is asking for 600dpi, it means [he] either didn't understand the question or there has been a failure to communicate. 600dpi (dots per inch) is the resolution at which your billboard will be printed. There was a time, in the Long Long Ago, when that would have been considered pretty high-resolution stuff -- I remember having posters printed ...


7

Should my images be saved at a specific PPI? No. iOS ignores PPI (pixels per inch) stored inside images. However, the pixel dimensions of your images do matter, so make sure you get those right. It’s also important to ensure your 2× images are exactly double the dimensions of your 1× images and that elements within the image are in the same ...


7

I recently read jrista's marvellous q&a from photo.stackexchange. While the question is titled "How do I generate high quality prints with an ink jet printer?" it covers DPI & PPI relationship to quite an extent and has real-world print examples. Current Q&A contents: Summary Detailed Explanation Empirical Studies: Does PPI really matter? ...


7

If you'll be going to a digital print shop to make the posters (which would be usual for a small run for a local event), you'll be fine at 150 ppi, and for a background image you probably wouldn't be in trouble at 100 ppi, particularly since it likely won't contain a lot of high-frequency detail that would conflict with your text. An 11x17 poster is mostly ...


6

How close are you going to view the 4' canvas? Is reducing the dpi really going to adversely affect printing on a coarse material like cotton or silk. Thats coarse relative to smooth glossy photo prints, for example. See this recent question: What DPI should a large format artwork for print be done at?


6

iPhone4 retina displays are 960x640 with 326 dpi (ppi). http://en.wikipedia.org/wiki/Retina_display#Display


6

Did you change the pixel dimensions as well? DPI is typically meta-information to tell a printer how large to print the image. It normally doesn't have any affect on the actual pixel dimensions of the image. If that's the case, than the difference is likely that you saved the image with a high JPG compression setting. The best way for us to determine ...


6

You are talking about microprinting. The whole idea of that, is that you cannot reproduce it by using printers or printing presses. It is engraving that are designed to trip up professional counterfeiters. So, no, I can´t see how on earth it would be possible to pull off. (of course, if you have unlimited resources and good connections in shady parts of town ...


5

Modified Modified Huffman. It's a method of fax compression.


5

ppi = pixels per inch = typically used as a measurement for screens (the iPhone 4 has twice the ppi as the iphone 3) dpi = dots per inch = typically used as a print measurement and refers to the number of pixels in the image that will be used to render 1" on paper scaling = this is a loaded term and why the answer isn't simple. For raster images, you can ...


5

Illustrator doesn't have a setting to adjust the Actual Size view of print documents to a screen's pixel density. To 'calibrate', I helped myself by holding an A4 sheet against an A4 document on the screen and zooming until they matched. Then I – ahem – wrote down the zoom percentage on a super-sticky Post-it, which now adorns the frame of my screen… (The ...


4

Roger's right. You WILL NOT be in trouble at 150 ppi for an inkjet-type print process, especially at that size. But let's pretend that you can't change the 300 ppi requirement. The problem you are running into is memory, and it may be an impossible hill to climb without upgrading your hardware, but here are some basic steps that can mitigate the problem: ...


4

If you want your photoshop to match the pixels on the Kindle, then your PSD file should be 1024x600 pixels. DPI is a measurement of the pixel density on the device itself and has no real bearing on your PSD file.


4

You can use the build in Preflight function. [I don't know when it has been introduced but its there in Acroboat 9 Pro and above] Advanced > Preflight [Keyboard Shortcut Shift + Ctrl + X ] Have a look at this video to see what I mean: http://www.mattbeals.com/videos/Adobe/ShowImageRes/ShowImageRes.html There are also other plugins and stuff, but as ...


4

Specifically on PPI for web or other on-screen images: 72PPI (or 75, or 96) is a myth. Yes, there is a figure which applications use to decide how many pixels to use to render fonts specified in points, but this hasn't got any relevance to images, other than: if your Photoshop document is 72ppi, it doesn't matter if your font units are set to points or ...


4

It depends on the usage the final file will be put to. If it's for web, definite dimensions could be similar or proportionately higher (never lower) to the dimensions expected to be shown in the final webpage (it can then exported in required dimensions using "Save for Web" functionality. If it's for print, it will again depend upon the quality of the ...


4

Every screen has it's own resolution. Or rather pixel density. Consider a 20" (diagonal) monitor: A monitor set to 2560x1600px has a ppi of about 137 A monitor set to 1920x1080px has a ppi of about 102 A monitor set to 1440x900px has a ppi of about 89 I post "about" because actual physical size of the monitor is a factor as well. A 20" monitor with a ...


4

While PPI definitely doesn't matter — it's pixel dimensions that matter for web and app design, you should be very careful about using design applications and mixing PPI settings. Here's why: However, if you plan to use Photoshop and different pixel densities for each document, dragging layers and copying layer styles between documents scales layer ...


4

In all my years of working with Photoshop, the only one that really stands out to me (aside from "print" and saving to other PPI-sensitive formats like PDF, obviously) is the type tool. But that's primarily because the type tool always defaults to points (even if you pull up the type dialog and type in pixels, it'll just convert it to points for you). Still, ...


4

You need to be using File > Save For Web & Devices The Save For Web option in Photoshop strips away all of the extra info in the images to make them as small as possible. In most cases, unless you need transparency, I would use JPG around 70-90 Quality. There isn't too much of a difference there. PNGs are nice for crisp & transparent pictures, but ...


3

PPI means "pixels per inch," and is a web display measurement. DPI means "dots per inch," and is a print measurement. If your Image Size dialog box reads "300 pixels per inch," you're fine. However, if you're starting at less than that, most likely you cannot arbitrarily make the PPI larger without sacrificing quality. (Depends on how far you're sampling ...


3

Import the Illustrator file into Photoshop as a Smart Object File > Open As Smart Object.\ Use Image > Resize with "Resample" turned on to change the width to 100cm. Be prepared to wait a long time, depending on your RAM and scratch disk (operation may fail if your system isn't up to it). Image > Mode > Greyscale Image > Mode > Bitmap Save ...


3

You figured it out. The dimensions you see in Bridge for the PDF are the output dimensions in points, not the image size in pixels. This is a sometimes misleading side effect of the fact that PDF is (in theory) resolution-independent, much as an Illustrator or EPS document is, that the "dimensions" of the PDF shown in Bridge are the print dimensions, not ...


3

Note that dye-sub is a VERY different printing process than most ink jet or laser printers (and offset printing, for that matter). In all those other technologies, the color on the page is created from a mix of 4 different colored dots...CMYK. Dye-sub, on the other hand, has each individual printer dot its own color. That makes Dye-sub a true continuous ...


3

In general, Pixels per Inch is for screen resolutions and Dots per Inch is for print resolutions, as lawndartcatcher says, but when you're dealing with an image that will be printed at a specific size, it is correct to use Pixels per Inch (because the image is in pixels) regardless of the number of dots per inch that the printer will lay down on the paper. ...



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