What Are Vector Graphics?

While vector graphics show graphic content, they are not images – they’re math.

Vector graphics are represented by the complex interactions of multiple mathematical formulas and calculations. These are used to flawlessly describe the boundaries of shape and color, no matter how complex. Bitmaps or raster graphics like JPG and PNG use points of color on a grid to describe images, fixing their size. Without inaccurate interpolation, raster images can’t be enlarged. But thanks to their mathematical basis, vector graphics can scale infinitely with no quality change. As a result, this infinitely flexible, lossless format is the de facto format for professional graphic artists.

Opening Vector Image Files on macOS

To render a vector image, the program must correctly translate the mathematical equations used to describe the image’s contents. It’s far easier to read a raster image like a JPG than it is to decode a vector image file. As a result, there are fewer apps for viewing vector images than raster images. Fortunately, our old friend Preview opens many vector image formats. However, it can’t edit them, only draw on top of them.

Photoshop happily opens vector graphics. However, Photoshop can’t edit vector graphics. So, it must convert the file to a raster image, permanently reducing the file’s fidelity. That’s why Photoshop asks for an image size when opening an EPS file: it needs to “downsample” the vector file to fit inside the specified raster image. Once downsampled, the image cannot be up-converted to its original quality. SVG is unusual: While it’s an image format, the files are specified with XML. As a result, they often open in a web browser by default. SVG has more in common with HTML, which makes the browser a reasonable choice for the default SVG viewer. Fortunately, any vector-imaging application should open and edit SVGs without complaint.

Edit Vectors on macOS without Adobe Illustrator

There are multiple professional-level programs you can use for vector image-editing on macOS. Adobe Illustrator is generally considered the industry standard for editing vector files on macOS. However, it’s far from the only application. There are even many free, high-quality vector-editing programs to consider.

Inkscape is the vector-editing analog for GIMP. It’s free, open source, and available on nearly every platform. If you’re a vector graphics noob looking for capable tools, this is the place to start. Affinity Designer provides an Adobe-style program for a one-time fee. It’s adequate for any hobbyist and many professionals, with a broad range of professionally-designed tools. Sketch is popular with user interface and app designers. It includes multiple affordances to simplify that process but also works for other design styles. BoxySVG is well-suited to simple SVG images. Its primary market is web designers looking for a simple interface design tool that won’t overwhelm them with complexity. But if you only need to view or edit simple vector files, you will appreciate how streamlined BoxySVG is. There’s very little to get hung up on, which can be a major benefit for weekend warriors.  Keep in mind the app version contains more features than the web browser version, and there are some file formats that only the app version can interpret.

Vector Editing Pipeline on macOS

The best vector-editing workflow on macOS will keep the images as vector files for as much of the process as possible. Files should only be exported as raster graphics if the publishing format requires them. Keep in mind that most professional printers prefer vector graphics, and converting to a raster format is not always necessary or desirable.

  1. Identify the file in Finder or Preview. Quick Look helps, but EPS files don’t always render.
  2. Open vector file in a vector-editing program. Do not open in Photoshop, which will force-rasterize the image.
  3. Make the necessary changes.
  4. Save file in a vector-image format:

.ai: If you can, save in an Adobe format: while they’re proprietary, they are also the best supported. If you’ll continue working in Illustrator, this is the best format by far. .pdf: If you need an open format, use PDF, though expect bulkier files. .svg: simple graphics (charts, logos, etc.) for web publication. You can also use SVG as an intermediate format for editing vector graphics. It works best with blocky, simplistic, or highly-graphic designs.

  1. Export as a raster image, if necessary. For the vast majority of illustrations, PNG is the best format. Only save vector art in a lossy raster format like JPG when absolutely mandatory.

Conclusion

If you can spare the subscription fee, Adobe Illustrator is the most capable vector editor on macOS. If you have smaller pockets, BoxySVG and InkSpace are both fantastic choices for vector editors on macOS.