Infographics: Scaling between Illustrator and Photoshop

By Justin Beegel, MBA, The Infographic World Team

If you’re using Illustrator and Photoshop together to make infographics, you’ll likely start to find the similarities comforting. The concepts behind most actions are the same. “Scaling,” however, is one area where the programs’ essential differences really show up.

Photoshop is a bitmap or pixel-based software. Each pixel in these raster images can be edited individually. That’s why you can easily paint out blemishes with a Paintbrush tool, and why the image looks blocky when you zoom in really close.

Illustrator, on the other hand, is a vector-based program, and editing is focused on whole objects rather than on individual pixels. Each shape or line is mathematically created by the software’s code, and thus can be scaled or redrawn to any size without any concern for the pixels.

Your design or drawing maintains its sharp definition at any size — and that is a key benefit in creating files like logo design.

Check out the figure to see what a difference scaling can make in both programs. The programs work in a complementary way, but that basic difference is something to be aware of when you are planning your project.

Seeing the differences between Photoshop and Illustrator.

Seeing the differences between Photoshop and Illustrator.

So, if your workflow involves placing Photoshop images into Illustrator, you can rotate the images and scale them up and down, but you can’t successfully scale an image any larger than the original placed image. The photo will look increasingly blocky and blurry once you start making it larger than the original Photoshop file.

You can place a low-resolution photo image in Illustrator and then sub in a higher-resolution version of the same image afterward, but you have to plan for it. Here’s how:

  1. Select a photo that you’ve embedded in Illustrator.

  2. In the Links palette, open the flyout menu and choose Relink.

    This allows you to search for and select the higher-resolution image.

  3. Click OK.

    The image will replace the original placed file.

    If the images are not the same in every way except resolution, however, the new image won’t fall in the same place.

If you’re creating vector objects in Illustrator for use as smart objects in Photoshop, your scaling options are much more flexible. In Illustrator, you can scale your vector graphics as much as you like with no loss of quality.

You can do the same thing after the Illustrator image is in Photoshop — if you pasted it in as a smart object. To make your smart object vector layer larger, you could scale it by simply choosing Edit→Transform→ Scale, but that would pixelate your image.

To scale it properly

  1. Double-click the smart object’s thumbnail to edit the image.

    It will open in Illustrator.

  2. Make your object bigger, and then save and close the Illustrator object.

    Your changes are automatically applied within the Photoshop document.

In general, smart objects make sizing up and down a nondestructive process. If the smart object is an Illustrator vector, you can take advantage of another great Illustrator trick: Transform Each.

Say you’re creating a map with several city dots on it. If you decide that the dots are too small in relation to the rest of the image, yeah, you could select each dot and scale each one up. That becomes annoying pretty quickly.

But, if the map is an Illustrator smart object (wait for it), you can select all the city dots at once and choose Object→Transform→Transform Each. (See this next figure.) Then, scale all the dots at the same time, scaling each from their own center point, which keeps them all in their proper places. Sweet.

Make changes quickly with the Transform Each command.

Make changes quickly with the Transform Each command.

Whatever your project, the best thing you can do for yourself is to find out the necessary production resolution at the start. Magazines, for example, need much higher resolution than will an online graphics — and you can’t fake pixel resolution after the fact.