The two key points that should be your primary concern when choosing a permanent marker to draw out a design are
1. Are they Waterproof/Bleedproof
2. What is the Acidity content of the ink solution used
I tested two different manufacturers of Colored Permanent Markers Bic & Creative Memories. While I have not tested them both on all the foundations available, I did test them on bleached linen for the purpose of this article and suggest you test the ones you plan to use on the backing of your choice.
Creative Memories website clearly states that their pens are made specifically & tested only on album pages/photo mounting paper.
Tests performed on all their products meet or exceed the industry standards.
Bic's website only claisms their pens are water resistant.
Creative Memories pens are acid free Creative Memories pens meet ISO standard 18902-2001 and are acid-free with a pH between 7.0 and 9.5.
I could not find any information on the acidity of the inks used in Bic's Pens
Sharpie's website has the following information and while I did not test them I recommend you do before using them.
Their Rub A Dub Marker while waterproof contains acid that can degrade your backing and your wool over time.
Their Standard Permanent Marker packaging contains the following information
Why does the Sharpie packaging say it is not for letter writing or cloth?
We do not recommend the Sharpie for letter writing as it is solvent base ink and will soak through paper. We also do not recommend the Sharpie for use on cloth as it may fade or bleed in the wash. Also, over time a yellow halo may appear around the marking.
Here are the photographs of the two pen series I tested....after allowing them to dry for 24 hours neither rubbed off with just my fingers.
I ran both inks under cold water for a minute then blotted, the Bic inks bled onto my white towel
I then left them sit in water for 24 hours
The Bic pens bled and ran while Creative Memories did not.
36 hours later some of the inks in the Bic series have completely washed out Creative Memories still look the same as when I drew them.
While your foundations may not get wet or be underwater for 24/36 hours the moisture content in our air could affect the inks and allow them to bleed into your wool. If your using a light color wool it could affect the wools coloring, should you wash or spill on the finished piece it would also affect the wool by bleeding into the wool.
You may not need every color used here to draw your patterns however for teaching purposes, beginner kits or complex designs the colors are very helpful.
Personally some may not care about the longevity of their rugs or if the inks used to draw their patterns bleeds into the wools, I however do and figure if I am putting my time & energy into something I want to do the BEST I can with the BEST products available, my pieces are made to last generations and become Treasured Heirlooms.
Blessings 2 U Friends
post script; Creative Memories Pens are only available through a Creative Memories Consultants. If you do not have a consultant you can order them from the link above & have them shipped directly to your home.
Bic & Sharpie Markers can be purchased at most retail stores throughout the United States.
Cheryl asked how much the pen sets cost?....$11 for a set of 4 colors
How long do they last?
Creative Memories colored Round-Tip pens will write for 300 yards or 3 football fields