The beauty of using rotary cutters in the sewing process is not just their convenience and simplify but also their versatility. The blades are interchangeable giving you a choice between various blade sizes and shapes.
A larger blade provides a fast and convenient way to cut on long, straight edges while a small blade allows more precision when cutting along uneven or curved edges. This is especially important if you prefer to use rotary cutters of fabric scissors to cut your fabric pieces once the sewing patterns are pinned and secured. Due to the organic shape of the human form, almost all garment patterns feature curved edges, some more abrupt then others. If you attempt to navigate along these narrow curves using a large rotary cutter, you will find that cutting the patterns accurately is difficult, to say the least.
When cutting your sewing patterns along very curved edges such as those of the neckline or armhole, use a small rotary cutter to accurately navigate along these more difficult edges. A small rotary cutter will not only provide increased accuracy and minimize cutting errors, it will also provide a sharper smoother cut.
If you do not have a small rotary cutter or are unable to invest in one, it may be safer and more efficient to use fabric scissors instead if a large rotary blade to cut along narrow curved edges. You may find that using fabric scissors along difficult-to-cut edges provides more control, comfort and precision.