Colored pens can be expressed with lines, such as painting a landscape. First use a pencil to lightly draw the outline of the tree, and also draw the intersection of the ground and the sky. Then fill the tree with light green and horizontal line segments , Don't be too dense, be sparse, or you can't reflect its beauty when painting other colors. Be careful not to paint. Then paint dark green, start from the bottom, and slowly change from dense to thin Then there is dark purple, which is also from dense to thin, and then use yellow color to paint on the top of the tree. The grass and the sky are drawn by these methods. This is the color ink drawn with lines. This type of painting is a closer look. It is not good-looking, and only by looking at a distance can you feel the real feeling.

There is also the same as sketching, for example, an object, you have drawn the object with colored pens, and also drawn its three-dimensional effect, then use a darker color on the back left of this object or There is a layer of lines on the back left, it depends on where you think the sunlight is shining from.