6776Re: methyl cellulose
- Aug 18, 2012--- In Marbling@yahoogroups.com, Aaron Salik <aaron@...> wrote:
> Jake, I agree. Most people marbling at a high level don't use MethylDear Aaron,
> Cellulose for marbling, but some do who want a cheaper alternative to
> carageenan. I don't think there is any question the results are sub
> standard, but everything has its time and place. For example when Martha
> Stewart featured a marbling project, and I can't remember if it was on her
> tv show, magazine, or online) she used methyl cellulose and referenced as
> as the source where she obtained the supplies. This is a perfect group for
> MC and not carageenan -) >
> What we sell as this generic form of methyl cellulose is Culminal
> methylcellulose MC 2000. It is methyl cellulose, not MHPC or other similar
> forms. It works for marbling.
Thanks for your reply. I think a few points of clarification are in order. First of all, it is important to note that methods of marbling using cellulose ethers are compatible with acrylic and oil colors, not watercolors. Iris mentioned how she couldn't get her colors to spread evenly. If anyone out there has gotten water colors to work on methyl cellulose, I'd love to hear about it, but even better, I'd like to have a look at the results. Many people- even marblers- will confuse these different systems and vaguely describe them as "water-based", but traditional watercolor marbling on a carrageenan size is a very different creature in comparison to modern methods using acrylics and cellulose ethers. It's like comparing apples and oranges- or perhaps more like grapefuits to oranges.
Many acrylic marblers use carrageenan, but I don't think it's necessary to use a pure carrageenan size for that purpose. In my own experiments with acrylic marbling, I found that a 1:1 mix of carrageenan (mixed 1 tbs to 2 quarts H20) and the cold-water dispersible HPMC (I think I mixed 1 tsp or 1 1/2 tspn per quart- about the same as the carrageenan, but my notes are back home in the States) gave the best of both. I later read that the late Christopher Weimann had found a similar ratio worked, even though Ingrid told me that he mainly use guar gum (Ingrid, if you're listening, please correct me if I'm wrong).
Aaron, I very much like and heartily recommend your company, your services, and your products, but I have to be honest and say that the use of this specific product for marbling is just not the best advice. Even if people are buying it from you for marbling, I would still say that there are far better HPMC products available that are far more ideally suited to the purpose. Your MC may work for a certain rudimentary type of marbling, but so will wallpaper paste from the local home improvement store: neither will work very well or produce very good results. I've used and worked with your product a great deal, but mainly as an additive for PVA adhesives. It's perfectly fine to use it for that purpose, so it does have it's place.
Please understand that I'm just being dead-honest about the fact that there are enormous differences in the working qualities of your product and the surface treated cold-water dispersible HPMC that many professional fabric and acrylic marblers generally use. Simply put, your product is grainer and more opaque; I've tried everything to reduce the opacity and granularity, from letting it sit for long periods to ensure maximum swell, to adding different forms of alkali. It can help to some degree, but it is still nowhere nearly as fine as the Dow Methocel J75M-S, which is crystal-clear, and ready to use in a short period of time after preparation, and also very durable.
There is also a significant difference in viscosity. You say your product is 2,000 centipoise (Cps). Dow measures their product in millipoise (Mps) units. so the"75m" in "J75M-S means 75,000 millipoise which converts to 7,500 cps- which is 3 1/2 times that of your product. The "S" suffix simply means "surface-treated" so that it can be dispersed in cold water, rather than hot water like the other forms that Sue mentioned. The higher viscosity means that it can be diluted quite thinly and still maintain a degree of viscosity that is also very supple and fluid, making it ideal for marbling. By comparison, I know from experience that your product just doesn't hold up when diluted so much, gel will even start to separate. As Sue noted, the other forms of MC and HPMC require more powder to achieve a similar viscosity, so the cost difference of using the surface-treated, cold water dispersible HPMC really is negligible, as it takes far less to make up a suitable size. So the cold-water dispersible grade wins hands-down.
Perhaps you would be interested in selling the surface-treated, cold-water-dispersible HPMC? Aside from marbling, it is a perfectly suitable form of HPMC for conservation purposes such as sizing paper after aqueous deacidification. Most paper conservators don't use it, simply because they don't know about it. I only learned about it from marblers. Standard alkali used for paper conservation, such as calcium and magnesium hydroxide, can be used to activate it, and once activated, it can be used immediately. I've used it for sizing, knowing that it imparts an additional alkaline reserve to paper after washing. I've even made remoistenable repair tissues with it. The best feature about it i comparison to the A4M, E4M etc., is that you don't need to wait for any bubbles to settle out before using it.
Well, that's my 2Â¢. Take it or leave it, and no offense to Aaron or Talas at all- I LOVE you guys!!- but my advice to the marblers on this list is that I'd spare yourselves the time and headache trying to get this particular product to work for marbling.
As an aside, I have a question for those of you marbling for several decades- when did marblers start using methyl cellulose for size? Who was the first to advocate using it instead of carrageenan? Was this as the result of an Ink & Gall article? Or was it before that time? Any ideas?
Finally, just to give credit where credit is due, I have to thank Peggy Skycraft for sharing the information about the Dow Methocel J75M-S grade, as part of her presentation on experimenting with different sizes at the 1992 Marblers' Gathering in San Francisco (<<<GASP>>>- 20 years ago!!!!). So if you're listening out there, thanks, Peggy!
With best wishes from Cairo,
- << Previous post in topic Next post in topic >>