I'm trying to oxidize a metallic trim that will be used on my wedding
dress. The trim came in with a much lighter backing metal than I
anticipated and I want an antique feel. Right now it just looks cheap.
The trim has a silver metallic backing (I'm not positive of the metal
used to construct the trim; at the fabric store they said it's not a
true silver) and there are rhinestones (they're actually tiny
swarovski crystals that look like rhinestones) inlaid in the metal. I
want to oxidize the metal without harming the crystal or discoloring
it and I'm wondering if this is possible. Any help would be much
appreciated!

As I mentioned, I have used Liver of Sulfur to achieve various patinas
on sterling silver jewelry and silverplated items. Liver of Sulfur
works on many other metals, too: I've applied Liver of Sulfur to
nickel, pewter, and copper to get an antiqued effect. While I cannot
absolutely guarantee that it will work in your case (since I don't
have access to a sample of your metallic trim), I have every reason to
expect that you'll be pleased with the results.

I've gathered some info for you, including online sources where you
can purchase Liver of Sulfur, and some articles discussing the use of
the substance. Liver of Sulfur smells really awful (like rotten eggs),
so you'll need to work in a well-ventilated area. Be sure to wear
gloves; you don't want to get this chemical on your skin. After you
have patinated your trim, you can rinse or wipe it with plain water.
There won't be any lingering odor, so you won't have to worry about
smelling strange on your wedding day.

A little experimentation should enable you to get just the kind of
finish you want. Most of the articles about using Liver of Sulfur
refer to dipping items in it; if you prefer not to dip, you can dab
the Liver of Sulfur solution on with a small sponge, a Q-tip, a brush,
or other applicator. It's best to apply just a small amount, then wait
a few seconds to see how it looks, and add more if you want a darker
tone.

====================================
 ONLINE SOURCES FOR LIVER OF SULFUR
====================================

Bella Beads and Wax
http://bellabeadsandwax.com/liver_of_sulfur.html

Kaylee Recommended
http://liver-of-sulfur.kaylee-recommended.com/

Scrapbook Express
http://www.scrapbookexpress.com/pineconepress.html

S&S Worldwide
http://www.ssww.com/store/product/sku=MC2799

Jatayu Wire Jewelry SUpplies
http://conniefox.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=TPO-0604&Category_Code=TPO&Product_Count=5

Delphi Glass
http://www.delphiglass.com/index.cfm?page=itemView&itemsysid=182826

====================================
   TIPS FOR USING LIVER OF SULFUR
====================================

How do you use liver of sulphur to patina sterling silver? 
http://users.lmi.net/~drewid/PWR_LOS.html

How to Use Liver of Sulfur
http://www.monsterslayer.com/Polish/Liver_Sulfur.htm

Creative Texture: How to Use Liver of Sulfur
http://www.creativetexturetools.com/resources/How_to_Use_LiverofSulfur.pdf

====================================
      TWO OTHER POSSIBILITIES
====================================

Here is a method for oxidizing metals that uses a hard-boiled egg! I
have not tried this, but it sounds interesting:

Wire Jewelry Design and Techniques Forum: Oxidize the natural way       
http://p209.ezboard.com/fwirejewelrydesignandtechniquesforumfrm10.showMessage?topicID=28.topic

A friend of mine raves about a product called "Master's Magic
Antiquing Solution." She uses it on brass, copper, bronze, and silver.
You can buy it here (about halfway down the page, listed as "Oxidizing
Solution"):

Volcano Book Arts: Metalsmithing
http://www.volcanobookarts.com/cart/metalsmithing/

======================================================================

Google search strategy:

Google Web Search: "liver of sulfur OR sulphur"
://www.google.com/search?hl=en&ie=UTF-8&q=%22liver+of+sulfur+OR+sulphur

======================================================================

I hope this helps you to achieve an elegant look for your wedding dress! 

Best wishes,
pinkfreud

Have you tried Liver of Sulfur? This can be found at many crafts stores:

http://www.monsterslayer.com/Polish/Liver_Sulfur.htm

http://users.lmi.net/~drewid/PWR_LOS.html

I make my own jewelry, and I've had great luck with Liver of Sulfur as
an oxidant. It is easy to use, and doesn't leave a black residue that
wipes off. It will not affect Swarovski crystals or most gemstones,
but shouldn't be used with porous stones such as turquoise and opal.

If my suggestion of Liver of Sulfur interests you, I'll be glad to
gather info regarding where you can purchase it online.

Yes, I'd be very interested in obtaining Liver of Sulfur with your help.

Thanks so much for the advice!

And, just to be sure, you think this will work even on a cheap metal
that has been sprayed with a low-grade silver (which is what I believe
mine to be)?

All of your advice is incredibly helpful.

One more question though: What does it mean to patinate my trim? 

I'm a little worried of the process considering I'm dealing with 4 1/2
yards of trim. Also, I'd prefer to dip considering the amount and
intricacy of trim I'm dealing with. Is blotting or dabbing the
preferred method in this case? (Okay, I lied. That was two questions.)

Oops, there I go, throwing jargon around. "Patinate" is just a fancy
way to say "add a patina to." "Patina" is a term used by artisans and
jewelers to refer to the "antiquing" or "aging" process, whether
natural or artificial. The term "oxidize" means much the same thing
(in a crafting sense), although technically oxidizing something
requires a chemical reaction involving oxygen.

Actually, when you're working with Liver of Sulfur or other patinating
chemicals, dipping is the preferred method. You'll get a more even
effect, and it is much less hassle than dabbing. I just thought I
should mention dabbing as an option, in case you preferred that sort
of technique.

Be sure to experiment with small snippets of the trim so you get an
idea of how long to leave it in the solution in order to get the color
you want. If it turns too dark, you can partially undo this by wiping
it down with a solution of water and baking soda. But it's best not to
let it get too dark, of course. Not unless this is kind of a Goth
wedding dress. ;-)

One more thing (this is the voice of experience): Liver of Sulfur
works best when warmed, but if you heat a solution of water and Liver
of Sulfur, it will give off really dreadful fumes. DO NOT MIX IT, THEN
HEAT IT IN THE MICROWAVE. If you do, the inside of your microwave will
smell bad for all eternity. To make a warm solution, heat the water
first, then mix in the Liver of Sulfur crystals or concentrate.

Since the stuff is so stinky, I recommend working with it outdoors or
in the garage. The only other thing I know of (other than rotten eggs)
that smells like this is Nair depilatory. If you've ever used Nair on
your legs, you probably remember the distinctive odor. Expect a very
similar smell when you use Liver of Sulfur. Thank goodness the smell
doesn't hang around.