At the beginning of Chapter 1, I spoke briefly about invisible interfaces and how Smart Guides are an excellent example of that. Smart Guides inform the user of the distance between the current layer and another layer while moving it, or upon request by using a keyboard shortcut. With the exception of this keyboard shortcut (which is simply option), Smart Guides appear whenever Sketch thinks you need them—which is basically whenever a layer is in transit (i.e. dragging, moving or nudging).
Smart Guides appear when you: