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
If it is not planned properly even simple a activity can kill.
A disgruntled or ignored stakeholder can easily derail your hard work.
Next generation cementitious materials
Still going strong...one of the great buildings of the 20th century.
Listed buildings and other heritage assets
Review of the bible for heritage assets and their management.
The David Lloyd Lymington Sports Village was 'Commended' in CIAT's 2018 AT Awards.
How do we make the smart city a reality?
Sir Nicholas Grimshaw has been awarded the UK’s highest honour for architecture.
Protecting the construction industry from Brexit.
Building Information Modelling
Conceiving buildings collaboratively, testing them virtually.
Effective collaboration in post-disaster response and recovery