Monday, May 16, 2011

The Invisible Zipper

I think that the invisible zipper is the easiest zipper installation of all styles of zippers. The key to a nice looking invisible zipper is basting and an invisible zipper foot.

I usually wash and dry all of my zippers before installing them. This keeps them from shrinking after they are installed. You can prepare them with steam and an iron too. For the invisible zipper, I also press the zipper crease open so that it moves through the invisible zipper foot easier.

pressing open

I mark the seam line where the invisible zipper goes with water soluable marker.

marking seamline

Then I pin the teeth of the zipper so that they are right on the seam line followed by basting.

placing

The top of the zipper should go just below the waist band seam. Try to keep the zipper stop just below the seam line so that you don't break your needle. When you sew this on, carefully back-stitch within the seam allowance.

I mark on the zipper tape where I will back-stitch on both sides of the seam where the zipper will stop in the side seam. (Although this picture doesn't show the marking exactly, I will try to replace the picture next time I install an invisible zipper.) This needs to be located at a minimum where the zipper foot will not pass because of the zipper slide. Sometimes it is easier to just sew the first side and then mark the second side to match the first if you aren't too picky. Regardless, the end of the stitching should be at the same place on both sides of the zipper. If you want a shorter zipper, then mark where you want the zipper slide to end and back-stitch at that location. You can use heavy thread to tie off the zipper and cut it off below the back stitching after the zipper is installed.

basting and marking

invisible zipper foot

On the second side, I also mark the seam allowance and pin the teeth of the zipper right on the seam allowance. Baste. Check to make sure that when the zipper is closed the fabric pieces are at the same level. This may rerquire pulling the basting thread and re-pinning and basting. Check it a few times because re-basting is much easier than picking sewing machine stitching out of the crease of the zipper. When the top of fabric pieces are even with the zipper closed, go ahead and sew the zipper as the first side.

This is a picture of what the wrong side looks like.

wrong side

The next step is a little tricky. Put the right sides of the fabric pieces together and work the area of the seam and seam allowance in such a way that the raw edges come together and the zipper is out of the way. It takes a little fidgeting, but completely possible. Pin the side seams to make sure that the hem is even. To sew the seam below the zipper, sew in the direction from the zipper to the hem (away from the zipper). At times I can back into the end of the zipper stitching (sewing in the reverse direction)starting an inch below the zipper stitiching and sometimes it works just going forward and back-stitching at the beginning of the seam. Below is the finished zipper and side seam. A few hand stitches are sometimes required to close the gap between the back-stithing of the zipper and the backtitching of the side seam.

invisible zipper 009

Monday, May 2, 2011

Finishing the seam allowance

The Summer Gore Skirt has straight seams for each of the gore panels. Although the directions call for a lining, depending on the fabric that you chose, you may not need to line it. If you do line it, you may want to use rayon or silk for the lining if you plan on wearing hose or tights with it. Otherwise cotton or no lining is fine. If the skirt will be wash and wear, I recommend finishing the seams even if it is lined.

Without a serger, you could finish the seam with a zig-zag stitch, triple zig-zag, or a French seam if the fabric is not too heavy. You may need to try a few different ways to see what works best with your choice of fabric.

I have a foot that keeps the thread from pulling the end of the fabric, which is pretty handy for over edge seam finishing.

Foot


French Seams
Sewing French seams leaves a very clean finish on the inside of the garment. 1) With wrong sides together sew a 3/8" seam. 2) Trim half of the seam allowance to 3/16". This may seem difficult, but with a little patience and practice, it is pretty easy to cut away half of the seam allowance.

Trim half of seam allowance

3) Press the seam open.

Press trimmed seam open

4) Turn the fabric right sides together and press the seam closed.

Final press

5) Stitch the seam at 1/4".

1/4" seam

Finished inside of garment with French seams (pressed and ready to topstitch).

Inside garment with French seam

Sunday, May 1, 2011

Cutting the fabric

Sometimes when I am asked what I am doing, and my response is "sewing," I laugh. More time is spent preparing to sew; tracing, cutting and pressing, the actual time spent at the sewing machine is minimal.

If I am using a pattern that has been folded, I prepare it by pressing with a medium to low temperature DRY iron. Enough heat to flatten the pattern, but not enough heat to burn it.  I do not use steam or the pattern will deform. Take care if there is tape holding the pattern together and keep the iron away from the tape.

When cutting the fabric, I make it as simple and easy as possible for myself. I use weights and rotary cutters. Fabric cutting weights are fairly expensive when purchased at a sewing shop, and I use a lot of them. I use zinc coated (galvenized) washers instead of the cutting weights. I washed them after I purchased the box or two (probably in the dishwasher to my husband's dismay). The smaller weights I glued together with epoxy, which may or may not be necessary. I rarely pin the pattern to the fabric, and when I do, I place the pins along the bias of the fabric (45 degrees to the grain) to minimize fabric distortion. Note: steel washers without the zinc coating will oxidize and leave black smears on your fabric.

Washers

Depending on the type of fabric my prep is different. I do not iron knits. Ironing knits distorts and stretches the fabric. I iron wovens prior to cutting. If I am cutting prints, especially large prints, I may cut each piece separately so I can place the print where I want it on the pattern piece. In this case, I trace the print or part of the print on the pattern piece to match prints or place the print in an attractive location. If not trying to match prints, I will fold the fabric on the grain.

Finding true grain of fabric can be tricky. There are definitely different grades of fabric. Sometimes I think the looms may get off kilter and the fabric may not be woven square (the warp and the weft threads are not at right angles). If the weave is too out of square, there is nothing that can be done. You may not want to use that piece of fabric, or use it in a garment that is loose so that the grain may not affect it as much. Some people try to stretch the fabric and square it up, but generally, the fabric will return to its previous state and you end up with a strange fitting or hanging garment anyway.

To find the grain on a knit fabric, whether it is Jersey knit, double knit, or interlock, I will find a line of knits and trace it on the location where I will be folding it (or near the fold) to cut it out. This takes a little bit of time, but keeps T-shirts and leggings from twisting around arms, legs and torsos.

Finding grain on knits

Stable woven fabrics can often be put on true grain by placing the selvages together and laying it out on a cutting grid. If there are wrinkles in the fabric, it is not on grain and you will have to slide the top layer of fabric one way or the other along the selvage until it lies flat. If it doesn't seem to be working well, on the cross grain either rip the fabric or pull a thread to line up the cross grain (weft) threads. This should help get the selvages to line up. Unstable fabrics like silk or rayon, I generally have to line up the weft threads on the end because the fabric will lie flat even when it isn't trued up. Twill fabrics are luckily stable. Usually ripping or pulling a weft threads is nearly impossible for me and the weave makes it very difficult to follow a weft thread.

This series of pictures shows wrinkles in the stable fabric that I am trying to smooth out by sliding the selvages over each other. Ultimately for this fabric, I had to rip the weft edge, line it up on the cutting grid, weight it and pull the other side until everything line up. It took a little while, but the results were well worth it. The third picture shows pulling a thread. The pulled thread marks the location to cut along the cross-grain.

Getting true

Line up weft and salvage

Pulling a thread

After spending the time trueing up the fabric, it is worth spending a little more time placing the pattern on the grain of the fabric. I usually start out with a weight on one corner and measure to the selvage in multiple locations along the grain line of the pattern.

Placing pattern on grain

When using the rotary cutter, it helps to keep a little bit of tension on the fabric behind the rotary cuttter. Essentially, just holding the fabric down behind the cutter to keep the fabric from getting bunched up in front of the cutter or pulling on the fabric a little bit. It is easier to do this with lots of weight on the pattern and fabric.

Weighting pattern on the fold

When I use the traced patterns, I find many advantages for marking the construction/seam lines to get a much more accurately sewn garment. The tic marks that I carry through the seam allowance get clipped with a 1-2 mm cut. Just enough to be able to line up the edges. A lot of patterns have notchess that are difficult to cut with a rotary cutter and require a lot of fabric adjusting to cut. I don't do that anymore and have just replaced the notch cutting with a little clip. Sometimes I also mark the location on the seam line where these tic marks are with the a water soluable fabric marker. In addition, I mark with a water soluable marker corners where seams come together. This helps make up for my inaccuracies when I cut the pattern out. Areas around the neck line, shoulder seams, and collars are highly sensitive to matching the sewing lines and small errors in these locations are usually visible. To make these marks on the seam line, prior to lifting the weights, I place pins perpendicular to the fabric through all the layers of the fabric. When I remove the weights, I mark the location where the pins go through on the fabric, usually on the right side, but as long as one side is marked the location can be found.

Marking and clipping

Marking fabric