If you are adding assets from outside of Turtl that need editing, here are the following dimensions used throughout Turtl as a guide.
The Dimensions for Design in Turtl Doc is your go-to source for all dimensions within the editor.
Turtl terminology refresher
Supported file types for Surf videos and images
Tips and tricks for Immerse page videos and images
Specific dimensions for each of the five-column formatting options in Turtl
Surf and Immerse Page Image Dimensions
Note: The default size is the smallest images should be, if you are wanting to optimize for large screen sizes you can multiply the default by two, but ensure that the optimize tick box is checked before uploading.
See these dimensions in action on our Dimensions for Designers Doc. The images show the dimensions of the columns and rows in the Immerse level grid system. Using these dimensions, it is possible to design graphics to fill a given region within the grid.
Each image shows the grid in a different configuration, one, two, three, four, or five columns. The height of a line remains 20px in all cases, but the width of the columns and gutters varies, as indicated by the measurements shown.
Note: You may wish to increase the graphics to 150% or 200% of the size required (file size depending) to ensure they look as sharp as possible on high-definition displays. These larger graphics will be scaled down to fit.