Re: Types of cellulose ethers
- HI Enid,
I don't know the answer, as I have never bought HPMC from those vendors. If the retail
vendors won't tell you, you can request a sample from Dow here:
and then compare the products (report back with what you find out).
FYI-There are many kinds of Cellulosic ethers, of which Methyl Cellulose (MC) is one
variety, and Hydroxypropyl Methyl Cellulose (HPMC) yet another. Most varieties of what is
sold by vendors as "Methyl Cellulose" is actually HPMC. The difference between MC and
HPMC is the latter has added methoxyl groups on the main molecule. That basically
means it has more places where water molecules can bond, so that it not only absorbs
more water, but also appears more translucent. MC solution appears more opaque and
behaves more like a gum.
There are different grades of MC and HPMC that are indicated by the initial letter. Then
the number indicates the viscosity as measure in mP.a units. The final letter is a roman
numeral indicating the quantity of the units- "C" grades are in units of 100, whereas "M"
grades are units of 1,000. The "cold water dispersible" grades sold for marbling are
"surface-treated" formulas of HPMC. The letter "S" at the end of the J75M-S grade
indicates that it is surface treated.
Hence, if I understand this correctly, "J75M-S" means that it is "J" grade HPMC, that is 75 x
1,000 mPa units (or 75,000 mPa- I think in a 2% solution), and that is surface treated so it
can be dispersed in cold water, rather than hot.
To learn more about the classifications, grades, and properties of cellulose Ethers, you can
download a PDF booklet from Dow entitled "METHOCEL Cellulose Ethers Technical
Handbook" that will tell you more than you ever wanted to know about the subject:
If you have trouble with the above link, you can find it listed here:
--- In Marbling@yahoogroups.com, "enidadams" <enid@...> wrote:
> You mentioned Dow J75MS methocel as preferable for marbling. Do you
> know if this is the type sold by Pro Chemical and Jacquard? In an old
> post Gail MacKenzie mentioned there are 9 different types, but
> unfortunately didn't mention which type she used.
> In my first attempt to mix Jaquard's brand, it took more ammonia than
> Pro Chem's to dissolve, but the ammonia may lose strength over time and
> this bottle was old. I lost my nerve to try sodium carbonate since the
> mfg. directions were for ammonia.
> Thanks for any additional clarification on brands and types.
- you can get a burnishing stone at Iris Nevins website:
Also, Peggy Skycraft sells MicroGlaze, another type of wax at her
Also, I haven't done it myself, but for very long links, you can go to
www.tinyurl.com and it will compress it for you for free.