Here is their reply. I'm wondering if it's a silicone substance. I haven't had a chance to check the test sites they give. It would be interesting to check with whoever is using it at the Smithsonian.
Happy Reading:
Thread Heaven is a chemical compound and its unique formulation has been patented by our company. The specifics of the formula, and the process used to produce Thread Heaven are carefully protected by us. However, from you question, I think you are interested in the characteristics of the compound, i.e., the substance we call Thread Heaven, not in the materials used to produce it because, as I'm sure you know, once chemicals are compounded the reactions often result in materials that behave very differently from the individual characteristics of the materials involved in the formula.
So let me reassure you about using Thread Heaven (I'll just call it T.H.) in your work with information about the characteristics of the product itself.
The most important thing to know about T.H. is that it is an inert molecule... it simply does not react to anything. This is why it doesn't melt, freeze, mold, degrade, etc. Therefore, a coating of T.H. protects the "encased" thread from UV ray, mold, mildew, temperature variations, humidity, and virtually all other environmental hazards and pollutants.
Additionally, because it is inert, it doesn't react with dyes or pigments, so it will not cause any loss or change in color . Instead, by protecting the thread from UV and moisture, it actually helps stabilize dyes that may otherwise be prone to bleed or fade.
We are often asked how T.H. will react with a specific type of thread or fabric, but as you can see, the question is rendered moot by the very nature of the product... its inability to react.
Perhaps equally important in your work may be the fact that the shape of the T.H. molecule allows it to move through fabric with a remarkably reduced friction ( or "drag" as it is often called). This in turn means that the stress on delicate, and perhaps degraded, fabrics during the conservation processes will be greatly reduced.
Of course, the caveat here is that T.H. will only protect the areas on which it is actually used so, over time, the untreated portions of a piece will probably degrade more rapidly and this may be a consideration in some cases.
The above information is a very brief summary of the results of hundreds of hours of testing by us and by independent agencies. For a synopsis of these test and a list of testing agencies and labs, please visit our website here:
http://www.threadheaven.com/testing.html and here
http://www.threadheaven.com/health_and_safety.html. Also, I strongly recommend you read the information on the "About the Product page as I think it may answer most other questions you may have.
Thread Heaven is already being used by restorers at dozens of museums, historical societies, etc., including the Smithsonian.
If the above info encourages you to try using T.H. in your work, please let us know and we will send you a sample in exchange for your written (email) evaluation and comments.
Thanks for your interest in our product.
Roni Hennen, Partner
Adam Beadworks