Technical drawing pen sizes
Technical drawing pens follow the same size-ratio principle as A series paper sizes, that is, an aspect ration of 1:√2, with the progression proceeding by folding the preceding size in two. When an A size piece of paper is folded in two it retains it's proportions.
The standard sizes for technical drawings pens also differ by a factor √2, ie. 2.00 mm, 1.40 mm, 1.00 mm, 0.70 mm, 0.50 mm, 0.35 mm, 0.25 mm, 0.18 mm, 0.13 mm.
This means for example that after drawing with a 0.35 mm pen on A3 paper and reducing it to A4, you can continue with the 0.25 mm pen. (ISO 9175-1).
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Blighting local areas, preventing investment and and encouraging anti-social behaviour.
Sharing knowledge about the conservation of the built and historic environment.
CIOB launches a call to improve quality in the built environment.
Vastint gets permission for a 6.6 hectare site to support the expansion of Leeds’ city core.
One of the Isle of Man’s best 1960s buildings.
Using renewable energy in developing countries - QSAND and Loughborough University Research collaboration.
From frost damage to sulphate attack, common causes of defects in brickwork.
Precautions to take when making advance payments.
Helping communities recover from disasters and protecting them before they occur.
Specialist services in hospitals
Instrumentation for critical healthcare environments.
Case study in the use of soft landings at the University of the West of England.