This is the most basic "quick" method of making simple PCB's.

Using either a waterproof "Sharpie"-type pen or specially marketed adhesive tapes and donut pads. You create your circuit directly on the copper surface of the board. Both the "pen" and "tape" techniques are successful at stopping the etchant from attacking the copper beneath the images, however, the real big concern is the level of quality.

Probably the most difficult part of this very simple technique is that you draw the circuit "upside down". Instead of pin1 of an IC being in the lower right of the grid of pins, because you are drawing the traces from the back ofthe board, pin1 is drawn from the top-right! It can be very confusing and is prone to lots of simple mistakes.