« TechNotes

Working With Vellum

These are notes that I compiled while working specifically with Wyndstone vellum, but most of these comments should be helpful for printing on any difficult-to-handle vellum.

Finding the Vellum

The Wyndstone vellum is available in 3 weights: 2.5 point, 3 point (also known as 29 pound) and 5 point (as known as 40 pound). It's available from Hyatt's art supply, but when I purchased from Hyatt's I found the paper had been mishandled somewhere along the way. I ended up getting the Wyndstone directly from Graphic Products Corporation (800-323-1658). They have great handling and packaging, and the paper arrived in good condition and was less expensive.

I found the 40 pound Wyndstone was the easiest to work with, with the least curling during processing and the least wrinkles at the end of the process.

Graphic Products sells it as "Vellum Tracing 40# 25x38, item 165243" for $3.90. I ordered 15 of these giant sheets and shipping was only about $10.

Coating the Vellum

To avoid wrinkles, I found it helps to print on a sheet of vellum significantly larger than the print size, to allow you to trim the ruffled paper edges that appear after processing. (For example, I’m printing 4" x 5" images on 10" x 12" sheets of vellum).

The Wyndstone repels water, so I add some Tween 20 to the coating mix. I coat with a magic brush, using 0.015 ml per square inch (about half the volume needed for a typical paper). I add about 6% by volume of 10% Tween (for a final 0.6% Tween in the coating mix). Because the vellum isn't very absorbent, double coating can really improve final image quality. (Coat, warm air dry for about 2 minutes, and recoat). If double coating, no tween is needed in the 2nd coat. I find that single-coated prints require about 10% longer exposure time, double-coated prints have exposure times comparable to HPR or Platine. The good news is that double-coating only uses the same amount of chemistry as normal papers.

To minimize wrinkles after coating, I dry the papers for about 4 or 5 minutes under a warm air stream after the 2nd coat (until the ruffles stop disappearing).

Exposing the Vellum

I rehumidify the entire sheet for about two minutes with a cold mist humidifier (maybe not necessary, but I think it can help prevent bronzing or solarization). The paper is a little bit wrinkled at this point. I expose under vacuum, but if you’re having trouble getting good contact, gently flattening the prints in a dry mount press is another option. I find that exposure times with the double coated prints are similar to working with any good paper.

Finishing

I dry the prints between sheets of blotter paper, loosely layered. After the prints dry, they are REALLY wrinkled. I trim the ruffled edges before gradually flattening in the dry mount press. At this point, the print is flat and ready to mat. (I've tried drymounting the prints with mixed success, and anyway, the loose print retains more of the vellum nature.)

At this point, you can coat the back of the print with mica powder by painting the back of the print with Aquasize and brushing on the mica powder. This has three effects: one is you can control the background color of the print by mixing different mica colors. Also, if the print isn’t lying perfectly flat on the mat, it’s almost like bringing the mat to the print, easing any shadows. And lastly it allows you to visualize brush strokes in the background of the print, a result of brushing on the size that the mica adheres to.

Vellum before flattening, and after flattening and applying gold leaf: