Preparing Images for Web & Print

DIY Preparing Images for Web & Print, by Alfredo Tofanelli on Plein Air Style

So, there’s this great art competition that you would like to enter and you need to prepare a digital image to submit using their specifications. This article will cover how to process your image in Photoshop for the web and for print. This can be a confusing topic and even many of the competitions seem confused on what they are asking you to submit--That’s probably because two different things are required depending on if it’s for the web or for print.

I’ll start with an introduction to preparing images for print and then move on to online versions, which are typically at a much lower resolution. Image resolution is defined on how sharp an image is either in print or displayed on your monitor or iPad. Each of these media or devices will display the image at a different resolution. Let’s say you created an ad for a magazine and your graphic designer asked you to send them an image at an exact size and resolution--Let’s say 6 inches wide by 4 inches tall. If the ad is for a typical magazine then they’ll want it to be twice the resolution of the actual printed page for the finest representation of your image. Most magazines print at 150 dots per inch (dpi) so you would normally give them an image cropped and color corrected at 6 in. x 4 in. at 300dpi. For the 300dpi image that is the same thing as an image that is 1800 pixels (6 in. multiplied by 300dpi) by 1200 pixels (4 in. multiplied by 300dpi).

Now if we prepare this same image for a web page then we would probably reduce it farther depending on how large we want it to display on the web page. Most of the time when dealing with web pages we’ll be using pixel dimensions versus inches because each monitor can be set at a different screen resolution. And we know what that means, right?
Let's hypothesize. If you had both your 13" laptop and your 28" monitor set at 1920x1200 pixels the same image on the monitor would be much larger in inches than on your laptop if you measured the image on the screen with a ruler. That actually makes our jobs easier in the sense that we may want the image displayed on a gallery page at 1200x800 pixels regardless of the screen resolution setting. The image will take up the same proportion of the web page. In a similar way as looking at a web page on your iPhone assuming it isn’t a web page designed specifically for a mobile phone.  

Click to zoom in
The illustration above is a screen shot from Adobe Photoshop CC of the Image Size dialog box which can be found under  [Image]  in the Photoshop menu. This is what the dialog looks like when I first open it up with this image. Actually I zoomed out on the painting so that you could see it better. It normally opens so that you see every pixel in a cropped area as the next screen shot shows. This dialog remembers what you last set it to so it may appear different than what you see above. Also, this dialog looks different from previous versions of Photoshop.

Notice that the Resample checkbox is unchecked. Next to it are algorithm choices for enlarging and reducing. For now, we will leave it at Automatic. Also notice the dimensions near the top. This image is currently 4040 pixels wide by 3016 pixels high. At screen resolution, 72ppi (pixels per inch), it would be 56.11 in. wide x 41.89 in. tall if we had a monitor large enough. Way more then what we need but that’s what we want. We always want an image larger than what we need to end up with.

To prepare this image for printing at 6 inches wide we will first:
  • Open the highest resolution file of your painting.
  • Click on [File] then [Save As] and rename this to something like Candy_Rock_forPrint.psd, also save in an uncompressed file format like PSD.
  • Click on [Image] then scroll to [Mode] and select [CMYK Color] 
  • Click on [Image] then [Image Size]
  • Check the Resample checkbox if its unchecked
  • Make sure the chain link to the left of Width and Height is selected. This will maintain the height to width ratio.
  • Set the Resolution to 300 Pixels/Inch
  • Next to Width we will select Inches for units
  • Enter "6" next to width
  • Notice the Height is automatically set for you because the chain link was checked.
  • Notice the dimension has been updated to 1800 x 1244 px and Image Size has been reduced to 6.92Mb from 34.9Mb
  • Click "OK"
  • Click on [File] then [Save]. Check with Publication or Print shop to see what file format they need and save another version with their requested file format.

Click to zoom in

This new file is now 6 inches wide and set to 300 dpi which is what most print shops and publications would want. Make sure to name these different versions so that you will easily know one from the other. I usually add something like Raw, Cropped, forPrint, forWeb, etc… to the ends of the file name so that I can easily distinguish them. Make sure that you do not save over the original image. I always start by selecting "Save As" to a new filename before I "Image Size" my image.

To prepare the image for the web at 1200 pixels wide make sure you start with your highest resolution image. If you start with the one that we had just created for print then you will be compressing an already compressed image which will not be as clean as if you had started with the highest resolution image. In video games they say garbage in, garbage out meaning if you start with something that isn’t the best version of it then what comes out will be inferior to what it could have been. And since we are artists we want the best representation of our work.

To prepare this image for the web at 1200 pixels wide we will first:
  • Open highest resolution file of your painting.
  • Click on [File] then [Save As] and rename this to something Candy_Rock_forWeb.psd, also save in an uncompressed file format like PSD.
  • Click on [Image] then scroll to [Mode] and select [RGB Color] 
  • Click on [Image] then [Image Size]
  • Resample should still be checked, but if not check it.
  • Chain link should be selected
  • Change Inches next to Width to Pixels
  • Change Width to 1200 px
  • Notice Height changes to 896 px
  • Notice the new Dimensions toward the top
  • Click "OK".
  • Click on [File] then [Save As] and save the file as a PSD or similar.
  • Also save or export a JPG version for the web.

Click to zoom in

You now have three versions hopefully in PSD format or a similar uncompressed format that you want to save.

Now you may have noticed that we didn’t explicitly set the Resolution in the Web version. That’s because it is irrelevant for web purposes. A web page uses the actual pixel width and height, so normally, resolution doesn't matter. In the future that may change.

To get a better understanding of how the Width, Height and Resolution are connected open up an image and bring up "Image Size" from under [Image] and uncheck Resample. Now take note of the Dimensions toward the top. Type 300 in the Resolution and notice how the width gets smaller but the Dimensions at the top are unchanged. Try typing a resolution of 600 and the width and height are cut in half and still the Dimension is unchanged. You can also try changing the width to 8 inches and see what the resolution changes to. Change the width to 2 inches and see that the resolution goes up by 4. What you should take away from this exercise is that as long as Resample is unchecked then you are not altering the actual pixel dimensions of the image, you are altering its resolution and that in turn alters the way it prints but not usually the way it is displayed online.

This is a confusing topic for most people so I hope that you are a lot less confused now. If you have questions then you can ask them in the comments below and I will try to answer them. Also feel free to suggest future articles. Happy processing!

Alfredo Tofanelli
Alfredo Tofanelli
Painter and Instructor, Alfredo is passionate about painting the portrait and figure. He's a regular instructor and advisor with Plein Air Liaison.
You can also find him here: www.tofanellistudio.com      CONTINUE READING MORE


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