Sketching Techniques:

1. Introduction:
Here, we introduce sketching tools, pencil holding techniques, basic shading techniques and procedure used for pencil sketching. The coming sub-sections carefully explain these techniques with an example of pencil illustration of a tree.  

2. Tools:
Various sets of pencils such as 4B stabilo, Hb pencil, 10b, 6b, 4b and 2b are used to illustrate the tree for various purposes.

Drawing sheet (commonly named as chart paper) is used here as a sketching surface. However, several other drawing papers such as bristol paper, charcoal paper, pastel papers, drawing paper and bond paper can be used for sketching purposes.  

3. Pencil Holding Techniques:

• For Detail Work:
  After shading some detail work is done to mark the prominence of certain elements in the sketch. For instance, while making a sketch of a face, detail work is done with the eye brows, hairs, eye ball etc.  Textures can also be created with detail works. It is a time consuming process and requires a lot of patience.
  
   
• For Extremely Free Work: 
  Sometimes the drawing surface is put on an Easel (frame/painting stand). This particular holding position gives ease at drawing and allows a free hand movement. Generally on easel or plane drawing surface this particular holding position is acquired for extremely free work.
  
   
• For Broad Shading:
  The whole length of the lead is made to touch the surface. It covers a broad area while shading. It is basically done to save time during shading and to create a thick shade.
  
   
• For work at Easel:
  This holding style is generally adapted while working at easel (frame/stand) which is usually used by an artist to hold the drawing surface in standing position. This holding position allows a free movement while shading.
  
   
• For Free Work:
  While working on a plane surface this holding position allows the artist to freely move his/her wrist. The little finger also gives a support to the hand and helps in balancing. Basically light outlines and shading are done with this holding style
  

4. Shading Techniques:
Direction of light falling on the object is important for shading. Lighter shade is used for the highlighted portions; darker shade is used to show the depth of the object and to show the shadow of the object that is casted due to the direction of the light. As mentioned earlier the light and shade effect is dependent on the direction and position of the source of light. Let us fix the source of light as shown in the figure below. Based on this position of light, you will see that the depth of the figure is achieved by breaking the figure into three tones viz. light, mid and dark using 4b, 6b or 10b suitably. Highlights can be achieved using an eraser also.

5. Tree in Pencil Shading:

• Step 1: (Skeleton)
  A skeleton of a tree is outlined on the paper. It enables to maintain the contour of the tree. Shading is done within the contour.
   
• Step 2: (Tonal Variations)
  Tonal variations of the shade (light to dark) is drawn. The degree of lightness or darkness of an area can be referred as tone in the language of art. Tone varies from the bright white of a light source through shades of gray to the deepest black shadows. In the illustration, the tonal variation is used to shade the highlights, shadows and depth portions. Darker tone is used for depths and lighter tone is used in highlighted areas. This tonal variation will help to guide the artist to select the right tone while shading the tree. The general technique of creating a tonal variation is basically done by using higher grades of pencils gradually.  For instance 6b pencil gives a darker tone than 4b pencil. Such tonal variations can also be achieved by applying pressure on the pencil. If pressure is applied on the same pencil a dark tone is achieved. 

• Step 3: (Shading)
  In the illustration of the tree, sun is considered as the light source. Due to sunlight’s direction (usually from the top), 4b pencil with a lighter shade is used for shading the tree at the top.
   
• Furnishing the Details:
  Further details are shaded through 5b, 6b, and 10b pencils. 10b pencil is used to shade the tree trunk. Dark areas and shadows are added to the tree trunk according to the direction of the light. The texture of the wood is created in the tree trunk by putting pencil strokes. Required pressure is applied on the pencil while putting strokes, depending on the texture that is created over the shaded areas of the tree trunk. It is very important to understand the physical state of the object to be drawn in order to create its texture.
  
  Shadow of the tree is drawn on the ground which is cast due to the source of the light from opposite direction (assumed in the sketch). The shading of tree shadow is comparatively darker than that of the ground shading. Dark strokes of detailed grasses are made on the ground with 10b pencil.

Check the Video for details of the step by step process of illustration.