You might be wondering, what is a canvas? It's the virtual paper you sketch on in Sketchbook. Whenever you open Sketchbook, a default canvas is created for you.
What is the size of the default canvas
The default canvas is based on the width and height of your monitor. This tends to be 1024 pixels x 1024 pixels. If you would like to change the default size of the canvas, you can do this through either your preferences or during creation. See Creating a canvas.
Why would I change the canvas size
One reason for changing canvas size deals with the power of your machine or device. Some processors can handle incredibly large canvases, such as 8192 pixels x 8192 pixels, without a hit to the speed or performance of the software. Others can't handle the stress a large canvas places on the processor.
Your project could be another reason for a different canvas size. If you are working on a matte painting that will be used as a background for a movie, will need a large canvas for creating this extremely large high-definition image. Same goes for printing posters.
What format are you outputting the image to? If it's for the web, the print quality doesn't need to be nearly as high as for print. For example, for the web, 72ppi (pixels/inch) might be just fine. Whereas for print, you would probably be looking more at 300ppi.
What canvas units are there in Sketchbook
Sketchbook offers pixels/inches, pixels/cm, and pixels/mm.
Why? For some professionals, industry standards dictate the units used. Other times, the locations of the artist or project determines the units. For example, since Europe has adapted metric as their system of measurement, you are more likely to need pixels/cm or pixels/mm.
What's the difference between ppi and dpi
Let's start with what each stands for:
- ppi is pixels per inch
- dpi is dots per inch
Both are used to describe the resolution of an image; however, they are not the same. PPI describes screen resolution (what you see on your monitor); whereas DPI describes print resolution (the number of dots of ink used for printing an image with a ink jet printer).
If you are creating content for the web and don't intend to print it, ppi is fine. If creating your image digitally, then sending it to be printed, dpi will be important.
How will the ppi/dpi of an image affect file size
The larger your ppi/dpi, the larger the file size. This is one of the reasons for understanding the intended use of the image. When an image is viewed online, a 72ppi and 8192ppi image look the same. However, the 72ppi image will load immediately, unlike the 8192ppi, which will chug as the page tries to load the image.