F.A.Q.s: Architecture & Engineering

• How do I keep my technical pens in good working order?
  
• What is “vellum”? What's the difference between vellum and mylar?
  
• What is the difference between the various types of bristol boards?
  
• My markers seem to dry out very quickly. I always cap them tightly, but what else can I do to preserve them?
  

Q: How do I keep my technical pens in good working order?
A: Technical pens are delicate drafting instruments which require care and maintenance. Ink should not be stored in the pen for a long time. After a couple of days, empty and flush the pen nib in cold water. (Never wash technical pens in hot water, as this will damage them.) Once a week, pens should be cleaned with a special solution designed to remove dry ink particles. The solution is sold separately or with a syringe that attaches to the end of the nib and gently forces fluid through the pen, expelling residue. Stubborn clogs can be removed by disassembling the nib using the included wrenches and soaking overnight in cleaning solution. A sonic cleaning tank can be used for the worst clogs and for optimal maintenance of drafting pens. Metal technical nibs last indefinitely if used on paper vellum, but mylar will eventually wear down metal points. Synthetic sapphire tipped pens are more durable and cost only slightly more than the metal type.

Q: What is “vellum”? What's the difference between vellum and mylar?
A: The contemporary term “vellum” refers to high-quality, smooth paper for drafting, usually 100% rag (all cotton or linen) and acid-free. The word “vellum” originally meant the prepared skin of fetal calf (veal and vellum have a common etymology), but the modern article is no longer an animal product. Mylar is a man-made, plastic film with one or both surfaces frosted to accept ink, graphite, markers, colored pencils and other media. Mylar can permit more vigorous erasure and correction than paper vellum, but traditional drafting media stick better to paper than film. Drafting leads are available for use on film that have polymer content for better adhesion, in place of the clay which is normally used in traditional graphite. Some government agencies still require rag vellum for drafting documents, and may not permit mylar as a substitute.

Q: What is the difference between the various types of bristol boards?
A: Bristol boards come in two surfaces, vellum and plate finish, in various thicknesses described by “ply”, the number of sheets pressed together to form the board. Vellum finish has a slight tooth which makes it good for graphite and colored pencil, while the hard, smooth surface of plate finish makes it better for India ink line work and markers. Bristol also comes in a high-alpha (wood) fiber variety which is more economical and a 100% rag variety which is durable and superior for drawing and painting media. The less costly version is usually a great choice for architectural models where surface properties are not a factor. Back to Top.

Q: My markers seem to dry out very quickly. I always cap them tightly, but what else can I do to preserve them?
A: The best way to stretch the life of markers is to use paper specifically intended for that medium. Marker paper has a hard, coated surface that makes crisp lines and bright colors and does not soak up a lot of ink. Avoid drawing with markers on newsprint, which soaks up a large amount of ink. To preserve marker tips, take care not to apply excessive pressure while drawing. Back to Top.

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