A very important operation on paths is simplifying. When you simplify a path (Path ▸ Simplify or 
), Inkscape attempts to redraw that path using fewer nodes, ironing out smaller details but preserving the large-scale features and the overall shape. If this description sounds a bit vague, it’s because the operation itself is not entirely deterministic; usually, it is difficult to accurately predict the result of simplifying before you actually try it. Even the reduction of the number of nodes is not guaranteed, although common.
Despite that, it is a very common operation and a true lifesaver for certain styles of artistic drawing. In technical drawing, on the other hand, it is rarely useful, if only because it considers any sharp corners in a path to be “defects” that should be smoothed out.
One effect that you can almost always count on is that if your path has nodes that can be deleted without any change in the shape of the path, they will get deleted by simplifying. This includes any nodes you have added with the Node tool (12.5.3 Deleting and Creating Nodes) or by the Add Nodes extension (13.3 Path Extensions) but never moved from their initial positions.
Path simplification is similar to gradient simplification in the Gradient tool, also accessible by (10.5.1 Creating Middle Stops). Gradient simplification, too, removes any gradient stops that you added but didn’t yet move from their initial positions.
Any simplification operation uses a certain force. Weak simplification changes the path just a little, removing only the most obviously redundant nodes. Stronger simplification will change the path more and smooth out larger bumps in it.
The default force used when you press once can be set in the Simplification threshold value on the Misc tab of the Inkscape Preferences dialog. The default is 0.002; anything greater than 0.01 is probably too strong for most cases. If you change it at all, consider lowering this value, because it is actually the minimum simplification force; you can always temporarily strengthen your Simplify command, raising this value without going into the Inkscape Preferences dialog.
How to make Simplify stronger? Just press several times in quick succession. Each invocation of the command will increase the force a little, provided it happened less than half a second after the previous invocation. With such accelerated simplification, you can apply exactly the amount of simplification you need for each path. If the first keystroke didn’t smooth the path enough, just keep pressing , and it will gradually pick up. If you wait more than half a second, though, the simplification force is reset back to the default value from Inkscape Preferences.
Figure 12-13 shows some examples of how simplification affects paths (see also Figure 12-2, which was produced by gradual simplification of the most node-rich rose silhouette). As you can see, apart from reducing the number of nodes and ironing out small details, this operation melts sharp corners and curves straight lines, producing a natural and often artistically engaging kind of distortion.