Full List-U

UglyLolita.etsy.com - Cute Macabre Art & ACEO
ulixis.etsy.com - has jewelry, drawings, and paintings in my shop. I pretty much love anything and am always up for a trade
UltramarineSTARS.etsy.com - Fabric and art supplies and Handmade bag and some digital printable clip art
UmlautGraphics.etsy.com - I am a graphics/banner shop I also have a BFA in graphic design. 
umbrellaboat.etsy.com - My shop is full of adorable pouches, purses, pin cushions, and plush toys!
UmmaThreads.etsy.com - custom made bags, purses and children's accessories. Crochet toy food available as well. looking for trades on almost anything, especially fabrics, sewing supplies, ribbons and other notions.
UmzansiCreations.etsy.com - Banner Sets, Collage Sheets, 3D Canvas Art and more
uncleaimee.etsy.com - open to trades with anyone on any of my favorites list (or if you've got similar wares to those!)
underoakstudios.etsy.com-precious metal & semiprecious stone jewelry
uneek4u.etsy.com - jewelry, paper goods, blankets, toys and more
UnexpectedTreasure.etsy.com - Unexpected Treasure offers an eclectic array of quality handmade, handcrafted and many originally designed items.
unicornsdesigns.etsy.com - Unicorn Designs is stocked with cute, affordable, handmade, beaded jewelley for all styles and occassions! Have a look around and you're sure to find something you like! :-)
uniqueartcreations.etsy.com - One-of-a-kind fabric accent frames
UniqueCatVintage.etsy.com - A vintage shop with supplies, clothes, toys, books, and more!
UniqueBanners.etsy.com - I'm a graphic designer who sells digital collage sheets on Etsy as well as offering custom graphic design work.
uniquecouture.etsy.com - UNique Vintage Handbags, Shoes....
uniquelyallies.etsy.com - jewelry, Sassy Scarves, Belts, headbands and more
UniquelyEJewelry.etsy.com - Romantically Inspired Handmade Jewelry 
UniquesStashNStuff.etsy.com- My shop is full of die cuts, tags and paper crafting supplies using only the best acid and lignin free cardstock. I'd like to participate in trades.
untamedrose.etsy.com - Handmade Boro Glass Treasure, specializing in hearts and roses.
UpcyledLife.etsy.com - Currently my shop is full of recycled paper envelopes and stars. But my crafting is starting to take a new turn and may include a bigger variety of items in the future.
UpstateHerbWorks.etsy.com - Hand-Crafted Body Products made with pure essential oils, fair-trade and organic butters and oils 
urbandebris.etsy.com - Handmade and upcycled art, jewelry, craft, collage.
UrbanEclectic.etsy.com - I create jewelry and accessories using formed sheet metals and wire wrapping.
urbanfringe.etsy.com - At Urban Fringe you will find custom, unique home decor and accessories. Everything in my shop can be customized to fit your space. Whatever it is, I can help make your house your home.
UrbanHomesteaders.etsy.com -  I sell homemade toys, craft supplies, and some household and vintage (will be more vintage, when I find time to create the listings!). Many of my finished pieces and supplies are wood. Toys are painted with soy paints and coated with homemade beeswax. I also do wood burning.
urbunny.etsy.com- I'm a felt accessories designer. My vision is cute, fun, and colorful =) In my shop I sell mostly felt accessories, but I also make and sell romantic\ vintage style lace hair accessories.
UrthWerm.etsy.com - Here at UW, you can find everything under the sun! Custom clothing, gifts, and graphics for your all your everyday wear & "flair" needs.
UxCritter.etsy.com - a family shop with Canadian Made Jewelry and crafts made by Sarah, Jesse, & Paula.