Enlarging an image
The problem here is the correct use of the ruler to transfer exact values-if lines are crooked they will produce a crooked reproduction.
Although not accurate to the nth degree the pictures transferred quite well. The more complex drawing of the teapot with lots of scribbly lines was more difficult. In fact I did not attempt to try and perfectly reproduce it, but it was interesting and challenging.
The use of the grid to help work out the perspective of round topped objects proved revealingly helpful. I made a perspex grid, enclosed in a mount and the lines may not have been entirely straight and spaced evenly. Is it possible to buy an accurate version?