It is really important that you ALWAYS check that your patterns fit together correctly before going on ahead and cutting your fabric. It may seem a bit tedious checking each seam, but taking a few minutes to check your patterns at this stage can save you cutting out incorrect patterns and wasting precious time and fabric later on .
When it comes to curves, the process for checking patterns is slightly different to when you check a straight seam.
Take the patterns you are checking and focus on the curved seams, and how they fit together.
Match the seams together, as if you were sewing them (one on top of the other). You may need to flip one upside-down (which is the case in the example).
If you are checking patterns that do not have seam allowance you can simply match the edges. If your patterns have seam allowance, make sure you are matching the stitching lines and not the edge of the patterns (this is when transparent pattern paper is very handy).
Before turning the pattern to continue following the seam, mark a notch (make sure you transfer it onto the pattern underneath too). Depending on the seam you are checking, it is often good to notch the seam during the process. Curved seams can be difficult to sew - if you mark notches at regular intervals, to make it easier later on.
Just like when you pivot a sleeve to see how it fits into the armhole, you will need to use a stiletto (or a sharp pencil or pin) to hold the lower pattern in place, while you rotate the upper pattern. As you rotate, the seams will come in line again. Once they are in line, hold in place and move the point of the stiletto to the next pivot point.
Continue rotating the pattern until you reach the end of the seam.
Hold patterns in place with a weight (or whatever you have got lying around).
Mark another notch. Once again, ensure the notch is transferred onto both pattern pieces.
Check that the seams are the same length.
As you can see in the example, the lower panel is slightly longer than the other pattern).
If it is only longer (or shorter) by a small amount (up to 1cm), simply trim off the excess.
If the discrepancy is bigger, you will need to remove half the excess from the length of one pattern, and add the other half to the other pattern, so that they are the same length.
The patterns are now checked and notched and ready for seam allowance.