Sakura also makes the Gelly Roll pens, and they claim archival quality,
however I am not sure if anyone has tested that. Here is Sakura's page
on these pens: http://www.sakuraofamerica.com/Pen-Gel.

Here are the Sakura pages on the Pen Touch pens, which are also listed
as archival by Sakura on their web page (again, not sure how they would
test).

http://www.sakuraofamerica.com/Marker-calligraphy 
http://www.sakuraofamerica.com/Marker-metallic-paint


An article I have found very helpful, even though it is about 10 years
old, talks about inks and commercial pens and numbering:

Illinois Association of Museums
Summer, 1997
#16
"How to... Mark Objects in
Museum Collections
PART I: Barrier Coats, Pens, Inks, Paints"

Here is an excerpt from the article, talking about commercial pens and
testing them. The testing process is not high tech and is probably a
good idea if using commercial pens for numbering. They are talking
mostly about black pens, but some of this would also apply to white:


"Commercial pens: Conservators generally dislike
commercial products because the manufacturers often
change the content without any notice, and it is difficult
to determine what ink, solvents, etc. are used in a
manufactured pen. Often even a small change will
affect the lightfastness, durability, or acidity of the ink.
Therefore, it is always best to test the pens before use if
possible. Like barrier coats, pens range in quality and
performance.


Suggested tests: Helen Alten suggests taking a piece
of Tyvek envelope and marking it with the pens you
want to test. Hang the envelope outside for a summer
and determine what inks survive. The legible marks
represent inks with good lightfastness. I have no
clothesline, so I mark Tyvek with a variety of pens and
place it in a sunny window. I do the same with wood,
glass, leather, and plastic using a variety of base coats
and pens. Another test includes writing with a variety
of pens on three types of paper: Tyvek, an acid free
label, and a piece of Resistall paper. Each piece of
paper is placed in a container of water for several
weeks. Unstable marking compounds will run or smear
almost immediately. Some inks will turn a purplebrown
color and will fade almost completely. Some
pens will not write on all surfaces, particularly on
plastics, including the barrier coats. In other tests,
marks were placed on keys using Acryloid B72 and
nail polish. The keys sat in a container of water for
three weeks to simulate flood conditions. Both
lacquers peeled and the nail polish actually floated off,
leaving damaged metal. Terry Segal, assistant registrar
at the Detroit Institute of Arts, recommends the
following tests: 1) Write with the ink or pen you are
testing on a variety of materials: glass, paper, plastic,
cloth tape, and metal. Bleeding or beading will be
immediately apparent. 2) Check for abrasion
resistance by rubbing. 3) Check for resistance to water
and solvents (when dry) by immersing in, or wiping
with a swab moistened with water, alcohol, or acetone.
4) Check for lightfastness by writing on paper or cloth
tape and placing in a sunny location. Draw a line with
each ink or pen and cover one section of the line to
block light. Compare the exposed and hidden areas
after four to eight weeks. 5) Acidity can be tested by
writing on a paper that measures pH.


-----Original Message-----
From: Museum discussion list [mailto:[log in to unmask]] On
Behalf Of Dana C. Street
Sent: Tuesday, July 08, 2008 4:22 PM
To: [log in to unmask]
Subject: Re: [MUSEUM-L] White ink for artifact numbering?

Hi all,
this is my first reply to Museum L !
Here at the Martha's Vineyard Museum, we have been trying a pen made by
Sakura, Pen Touch and have had decent luck with it.  You just have to
get hang of how to control the ink flow.  It is not labeled as
"archival" and I'm wondering if the gelly pen from Gaylord, listed in
another reply, is?

Dana Costanza Street

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