Sketching techniques

1. Hatching  
2. Cross-hatching

Hatching is use to depect the shading of effects in an image. by drawing series of parallel lines of different length ---cross hatching is similar to hatching.

Braslate shading 

Braslate shading gives a 3d effect in 2d image . In these techquie while shading emphasis is laid on the contours of the image to give it a more realstic look

Gredation

These is a smooth transtions of colours