Center lines are necessary in working drawings.
In choosing T-squares, care should be exercised to see that the head slides up and down the left-hand side of the board easily, and that when pressed against the board with the left hand there is no “slogging” of the blade up or down, or in other words, that the head is bearing firmly for its whole length against the board.
The best place for the title of a drawing is said to be the upper left-hand corner; this facilitates the filing of the sheet.
Never use a soft pencil except for finishing in shadow lines.
The rubber should always be kept clean.
Great care should be taken to keep drawing boards out of the way of heat or damp, as these cause the wood to warp.
Circles and curves are to be “inked in” before straight lines. First ink the smallest and afterwards the larger curves.
Do not press heavily on the pencil so as to cut the paper, but draw lightly, so that the mark can be erased and leave no trace, especially if the drawing is to be inked.
The draughtsman should commence his work at the top of the paper, keeping the lower part covered over until he needs to use it.
Shade lines should be avoided in all working drawings, as their use interferes with accurate measurements.