Do not try to economize by using a poor knife. Only one that may be kept in first class condition should be tolerated. The knife should have two blades - one at each end. The smaller blade is to be used for drawing lines and the point of this blade must be kept very sharp. Knives with many blades or with tools in their handles should not be used. Neither should you try to use a knife having a chain attached to the handle.

Always keep your knife sharp. Fig. 161 illustrates a well shaped knife.

For directions in using the knife see Lessons 6, 8, 16, 18, 20, 21 and Figs. 18, 19, 20, 21, 22, 32, 33, 42, 65, 92, 113. Be very particular to use your knife as directed, for very much depends upon making a straight, clean and correct line.