I had a run in with a piece of rayon spandex jersey this past week. I ended up cutting it with an underlay to keep it from moving around. It reminded me that an underlay is useful for other things besides chiffon, georgette, and charmeuse.
WHAT IS AN UNDERLAY?
An underlay is a piece of paper placed under the fabric that you are going to cut. It keeps the fabric from shifting in the cutting process and going off grain. A roll of plain brown kraft paper works fine. Try to find paper that is as wide as your fabric or your table. If you can’t get the width you need, just add on as required. The paper must be as wide as the fabric you are cutting.
WHY DO I NEED TO DO THIS?
An underlay is absolutely required for the best results in cutting very slippery fabrics like silk charmeuse and silk chiffon. I also use it with rayon jerseys where grain and cutting accuracy is important. Place your fabric on the paper after making very sure that you are starting with a straight grain. Its OK to cut multiple layers with a single underlay, just make sure that all are correctly started on the straight grain.
If you are cutting pairs, like 2 sleeves or 2 fronts, make sure you lay your fabrics face to face so that you don’t end up with 2 left sleeves. (Ask me how I know!)
ESTABLISH A STRAIGHT GRAIN
If it’s a fabric you can tear, like chiffon, that’s the easiest way to establish the straight grain. Use a t-square to draw a perpendicular line across your paper and align the torn edge along the pencil marking. If you can’t tear it, like charmeuse, you will have to pull a thread all the way across (nerve-wracking I know) to get the grain to reveal itself. For jerseys, I follow the lengthwise grain of the rib and use a C-thru ruler to chalk in a perpendicular line.
Use weights to hold the start of the fabric at the line you have drawn at a right angle from the edge, across your paper underlay.
LAY OUT YOUR FABRIC ON THE UNDERLAY
Once your fabric is laid out on the starting grain, smooth it out absolutely flat ( a c-thru ruler brushed lightly across the surface to eliminate bumps can help); make sure to place weights on the fabric to keep it that way. Keep the straight grain set on the line drawn, and make sure the selvedge lines up against the straight edge of the paper. Now you have your grain lines established.
PLACE YOUR PATTERN ON TOP OF THE FABRIC
Place your pattern on the top and use the weights to hold the pattern down. (Nicely smooth, no wrinkles)
Do not use pins!
Pinning will distort the fabric. You can use just about anything for weights, small food cans are fine. I use heavy tape dispensers, staplers, anything that comes to hand.
You don’t want to move anything once it’s laid out, so try to get everything laid out in the block of fabric on the table that will fit. If you can’t get all the pattern pieces on it, you will have to lay out another block to cut the rest.
AVOID CUTTING YOUR FABRIC ON THE FOLD, NO HALF PATTERNS!
Please note, it doesn’t really work well to cut on the fold when using an underlay (although some have been known to cheat). You risk going off grain and may have to live with the consequences…..So no half patterns! If your pattern piece is meant to be laid on the fold, then take the time to mirror the other half of the pattern by tracing it off on a folded piece of paper.
CUT THROUGH ALL LAYERS
Cut out the paper along with the fabric. (It’s OK, I know they told you never use your fabric shears on paper, but when you cut fabric along with the paper it works fine. I have a pair of huge 12″ Wiss shears for almost 25 years now, and I rarely sharpen them.) Since the paper is lifting off the table and supporting the fabric, the fabric does not shift.
A FEW TIPS FOR SUCCESSFUL CUTTING
Make sure your weights are not too close to the edge of the pattern, that makes it more difficult to get a clean edge. For those tight corners and curves you can actually flip over the paper that’s already been cut and get in closer. That’s after you’ve been practicing awhile!
A bonus of using an underlay is that it can become a record of what you’ve cut. If you are adjusting a pattern on the table, or maybe putting together bits of various patterns for an entirely new garment, an underlay can become your pattern. Just be sure to mark the grainline, and pencil in what the name of the pattern piece is and how many to cut.
I don’t use electric scissors or rotary cutters, so I don’t know how that works with an underlay. I have used small industrial cutting machines with an underlay, so I suspect that it may work fine.
And of course, your scissors need to be sharp and without nicks that could catch on your slippery fabric for the best results.