Blender 3D Printing by Example

Aiming for quads

Next, I would recommend as much as possible to keep your faces as quads, or faces with four vertices. Thanks to our combination of Loop Cut and Slide and Extrude, all the faces in our hand should already be quads. As we make additional edits, particularly if we are tempted to merge vertices or use the Knife tool, we'll want to be conscious of trying to stick to quads. The advantage of quads becomes clear as you continue to use the Loop Cut and Slide tool to add additional edges. Loop Cut and Slide knows how to navigate quads. If I wanted to add another edge loop down the ring finger, that loop could successfully circle the entire hand:

Loop Cut and Slide can navigate quads

If I merged two vertices together to make one of ...