A continuous placket is required to have enough length to be folded back upon itself effectively, ensuring both sides of the opening are properly secured and finished. To achieve this:
1. Understanding the Requirement: The pattern piece must allow two layers of material to cover the placket opening entirely, hence the need for it to be at least twice the length of the opening.
2. Seam Allowance: It's practical to add extra fabric for seam allowances to ensure neat finishing and to account for potential errors in cutting or sewing. Commonly, an additional 1 inch is added for this purpose.
Formula: Length of Pattern Piece = 2 × (Length of Finished Placket) + 1”
Thus, the correct answer is: Twice the length of finished placket + 1”extra.
For a continuous placket, the pattern piece required is typically twice the length of the finished placket, plus an additional 1 inch extra for seam allowances and turning the fabric. This ensures there is enough material for folding, stitching, and finishing the placket properly.
Let's review the options:
(1) Same as the width of the finished placket + 1 inch extra: This is incorrect. The length of the pattern piece is not determined by the width of the finished placket; it is based on the length of the placket.
(2) Twice the length of the finished placket + 1 inch extra: This is correct. The pattern piece required for a continuous placket should be twice the length of the finished placket plus 1 inch extra for seam allowances.
(3) Three times the length of the finished placket + 1 inch extra: This is incorrect. You only need to double the length of the finished placket, not triple it.
(4) Same as the length of the finished placket + 1 inch extra: This is incorrect. The pattern piece needs to be twice the length of the finished placket to allow for the necessary folds.
Thus, the correct answer is (2) Twice the length of the finished placket + 1 inch extra.