When sewing slash pockets, one of the most important elements of achieving a smooth, tension-free pocket opening is cutting the pocket correctly and eliminating excess bulk at key areas. Here some basic techniques you should follow regardless of your slash pocket type and shape:
When sewing traditional slash pockets such as welt or bound pockets, the pocket opening is first slashed down the center.
When arriving at each side, slash into each of the rectangle's corners, getting as close as possible to the stitch without accidentally cutting into it.
Ina rectangular shaped slash pocket, there should be a triangle extension (cutout) at each end as shown above. The triangle extension will allow you stitch and stabilize the pockets sides.
Cutting into each corner will allow the pocket's finished edges to lay smooth and flat. Each corner should be well-defined and tension-free.
Slash pockets can be constructed in a variety of shapes and sizes. Regardless of shape, you should always slash into each corner as close as possible without cutting the stitching.
Cutting into each corner, regardless of shape, will allow you to turn the pocket layer into its right side to expose the clean-finished pocket opening edges. If you attempt to do this without clipping close into each corner, you'll find that not only will the pocket layers not layer flat, tension will accumulate at each pocket corner.
When working with irregular shapes, aside from slashing into inner corners, it also important to eliminate bulk at key locations within the pocket's seam allowance. For example, the star-shaped pocket shown above is has both inner and outer corners. The corners are clipped into the inner corners, while the outer corners receive triangle -shaped wedges.
When the star shaped pocket opening is turned on its right side, the corners should be well-defined without any bulk caused by excess seam allowance- this is why cutting wedge notches at the outer corners is so essential.