There is no reason, however, you can't use "fancy" fabrics with my patterns! I made this Journey Purse from upcycled fabrics supplied by my sister-in-law.
Just remember these tips to keep your fabric and sewing machine 'safe' and your purse results outstanding!
1) Watch the Heat!
Remember that many fancy fabrics are made of polyester, silk, and other fibers which won't take the high heat of the iron that cotton will!
Before pressing, set your iron at the "silk" setting or below and test on your fabric - preferably on SCRAP fabric. Carefully see if the fabric will take any direct heat - some fabric will actually melt! You may need to use a pressing sheet between your fabric and the iron. I just use a scrap of muslin as a pressing sheet.
For example, on the purse pictured, the straps were a thin polyester and I had to use a pressing cloth and a lower than silk setting on my iron. I also had to be satisfied with a little wrinkling when I adhered the interfacing (see #3 - Always Interface?). It adds interest to the straps, right?
The silk brocade which makes up most of the purse could take light ironing (on the just-below-the-silk setting), but I tried to do from the wrong side whenever possible. Remember sometimes the heat from the iron can change the color of natural fibers.
The heavily embroidered flap could barely be ironed at all! I didn't want to melt any of the sequins or metallic thread (it will actually break from the heat, not just melt!). Finger-pressing is sometimes all that will work. I did get by with lightly pressing from the wrong side (it is lined with a piece of the silk brocade).
2) Pre-Check your Fabric
The flap is a heavily embroidered piece of fabric with thick metallic threads, sequins, beads, and rustic yarns. It appears to be an old cover (for something) from India. Scary!
Before cutting the flap, I carefully measured the size of the flap, centering the motif. Then I painstakingly removed all the sequins and beading at least 1" inside the measurement. You don't want to sew through a sequin, if you have the choice. Could break a needle or knock your sewing machine off timing if the needle won't penetrate the sequin.
I was able to clip the continuous thread holding the sequins from the back and use a seam ripper to pull a long tail of thread to the back. I then tied these threads off securely. This was an old piece of embroidery, so I checked the security of all the beads and sequins and tied off in back if necessary. I kept all the threads out of my 1" allowance on the edges. Then I carefully cut the flap to size.
The embroidery has a very loosely woven base, so it would be subject to stretching. I made sure to use a stable piece of fabric (the silk brocade) for the lining side of the flap that was also interfaced to keep the shape.
Make sure and examine your fabrics for "dangerous" areas BEFORE cutting and sewing!
3) Always Interface?
I like to interface all my purse pieces to make a sturdy, well-shaped purse. However, fancy fabrics don't always have to be interfaced!
The heavily embroidered flap would not take well to interfacing (I didn't want to touch it with an iron!). So I left it un-interfaced. However, I did press a small square in the area of the snap (the snap is attached on the underside lining side of the flap) to protect the fabric from rubbing the wrong side of the snap. I used a pressing cloth between the interfacing square and the iron and pressed lightly, just enough to melt the glue of the interfacing.
You could also choose to use sew-in, rather than fusible, interfacing.
If using a very heavy canvas or duck, no interfacing is required. You're just trying to make the fabric have a little more body and stiffness which are already characteristic of these fabrics.
4) Adjust Some Pattern Details
Remember if you're unsure if the fancy fabric you're using is strong enough for a purse, you can strengthen it with the lining! I purposely used a cotton batik for the lining of this purse for stability and strength. The lining is interfaced as well, and makes finishing on the purse more satisfactory. This can be especially important if you're using an old, upcycled fabric which may have started deteriorating.
For the flap, I found the loosely-woven embroidered piece would never be as "crisp" as a thinner cotton. So I decided not to topstitch the edge. The seam allowance was too thick to get a nice edgestitch. Instead, it makes a nicely rounded edge. I also wanted to stitch as little as possible through the heavy metallic threads - they can actually break a needle!
I chose to round the corners on the flap because the fabric (it's loosely woven) raveled easily and also it would have been impossible to get a crisp corner with the thicker fabric. I also made sure not to trim too close to the corners.
It was important not to clip too far (when assembling the sides of the purse) into the silk brocade as it also raveled easily. I made sure to restitch the corners because of this.
As you work with your fabrics, you may need to adjust how you usually sew. Be sure and secure all corners and edging with extra stitching!
5) Use the Right Tools
A sharp needle is required for natural fibers like silk and rayon and even for thin, silky polyesters. A universal needle will sometimes snag the fibers. Also make sure and use a smaller needle, a 70 or 80 with lightweight fabrics. If your needle is snagging the fibers, try a new needle; sometimes a needle right out of the package will have burrs. If it still snags, try a smaller needle.
I like to use a Jeans/Denim needle for purses, because of the thickness of the seams and interfaced fabric. I found a size 80 Jeans needle (this is a sharp needle) worked fined with the fabrics for my bohemian purse.
You also may need to use thinner straight pins. You want your pins to glide through the fabrics and you shouldn't have to force them through!
Make sure you don't cut through any sequins with your good scissors - it's a sure way to dull them. You may want to use old scissors or rotary blade when cutting something with heavy metallic threads, too. Some old metallic threads can actually nick your blade!!
The rule with fancy fabrics? Don't be afraid, just be CAREFUL!!
Remember the flaps of the Journey Purse, Joey Purse, Lizzie Bag, Mimi Bag, Sheila Purse, and Adventure Bag are a great place to use a special (embroidered or embellished) fabric. And the Zippy Wristlet, Jamie Bag, and Zipper Hobo look fantastic in shiny, fancy fabrics, too. And a canvas, duck, corduroy, or decorator fabric is fantastic in lots of my purse patterns!