We all know how disappointing it is to create a garment and have it not fit. When you have used a pattern before and the second time around creates a different fit, it is not necessarily human error.
Your fabric choice may be where the change occurred. If you used a knit or stretch fabric for the first garment, you may have been using the "give" in the fabric without realizing it. The traditional sloper is made with muslin. Muslin is used because it is economical and it is a woven fabric. Woven fabric is not forgiving in the same manner as knits. Muslin gives you a true picture of how a garment will fit. Straight from the bolt, most muslin is a loose weave. I suggest that you preshrink the muslin, before you make a trial garment. The tighter that weave of the fabric, the less give you are going to have in the finished garment and you will get a true picture of the fit.
If you have used the same type of fabric and gotten different results, odds are there is human error involved. Press the pattern pieces and the fabric before you lay out the pattern. Making sure all the elements are laying flat and on grain is the first area a change can occur. Although a wrinkle in the fabric may seem insignificant, if this wrinkle adds an eighth of an inch to two pattern pieces, you now have added a quarter of an inch. The more pieces of the garment that this wrinkle is in , the more that eighth of an inch is magnified.
Construction is the next area that human error will magnify and change the fit of a garment. Most home use patterns are designed with a 5/8" seam allowance. An eight of an inch difference in the seam allowance magnifies by the number of seams the garment has. Always follow the manufacturers direction!
For example: Because a seam allowance is joining two pieces of fabric, each seam allowance that you use a 1/2" seam allowance, will add a quarter of an inch to the finished garment. If you are making a skirt with six panels, you are using six seams and the 1/8" variance will add up to a 1 1/2" difference in the finished skirt. Once this has been added to the body of the skirt, you are going to have a problem with the waist band, unless you have made an adjustment before cutting it out. It is amazing how rapidly an 1/8" can change the entire fit of a garment.
How to eliminate the human error!
- If a pattern fits, take the time to preserve it. One of my favorite ways is to back a pattern, I want to use again, with light weight iron on interfacing. Be sure to press the pattern and interfacing smooth before you use it again.
- Use a ruler to check your machines seam allowance. Although it is rare, many times the error may be with the machine. With the needle down, on the 5/8" mark of a ruler, check the edge mark you have been using for 5/8". How to Set a Sewing Machine Seam Guide for Accurate Seam Allowances
- Make sure you are staying on target when sewing a seam. You must keep your seam allowances accurate to have accurate finished results.
- Press your pattern and your fabric before cutting anything out.
- Make sure everything is laid out smoothly before you cut out your fabric.
- Take the time to read the manufacturers directions and keys. Although they usually stay the same, changes are made and reading the pages first eliminate errors.
- Pre shrink muslin before you make a sloper.