The objects with the outlined contours is another kind of Line web icons. They're called contour drawings. It's also possible to find another type of icons: the items are without some strict outlines. They're called gesture drawings. These kinds of drawings are being widely used by skilled designers who can repeat the outlines of the object right after seeing it. It's not a complete piece of art but rather a sketch which requires 20-30 seconds to be drawn.
One more technique is adding some halftones and shades to the object. You can do it with the help of short lines and crosshatching. Their frequency and pencil pressure can be different. And this variety impart more three-dimensional look to the object. It helps to produce awesome Line icons, logos and buttons.Also lets get info about open lines. It's such sort of the lines where the dots not combining the singular elements. The lines can be also parallel, gesture-like, contour and so on. The curves that are important for creating complex line shapes are called Bezier curves in computer graphics. These curves are handy small features essential for developing the vector shapes like line icons, different buttons etc.Computer technologies have the ability to reproduce the same designs or build new shapes based on some older ones without extra efforts and time. Furthermore, you are able to return to the previous adjustments due to the history panel. As a result there's no need to design Line icons from scratch in case you have made some errors.