One of the most convenient aspects of using rotary cutters in crafts and dressmaking is the availability of multiple blade sizes and decorative edges. Not only can you choose from different blade sizes and shapes, they are also very easy to remove and interchanged as needed without having to purchase a new rotary cutter set. This provides a lot more versatility then regular scissors, especially if rotary cutters are your preferred tool for fabric cutting.
Rotary blades are available in a variety if sizes and a few unique shapes. The blade size should be chosen based on your project- a larger blade is used when cutting through thicker fabric or multiple fabric layers, and when cutting straight, long edges. A small blade provides more cutting control along narrow curves and irregular edges. A smaller blade offers more precision and decrease room for error. If you love your rotary cutter's handle and structure, it is a good idea to invest in a few compatible blades of different sizes to accommodate these special cutting circumstances. However, if you require a much smaller blade (like the one pictured above) you may have to purchase a separate rotary cutter due to blade compatibility issues. Nevertheless, investing in a mini rotary blade is highly recommended, especially if you prefer to use rotary cutters when cutting your garment pieces following sewing pattern lines.
Another instance you will find yourself have to replace or interchange blades is when they become worn after long term use. A short blade is crucial in the dressmaking process- seam edges have to be precise and smooth and follow sewing pattern lines as accurately as possible. Compared to fabric scissors, rotary blades wear out faster. Nevertheless, the convenience of replacing them should not pose much of an issue, especially when you have extra fresh blades handy. Keep in mind that Rotary blades continue to be very sharp even if they don't cut fabrics as sharply as they used to. For that reason, you should be very careful as you replace the blade. When disposing the blade, wrap the blade with masking tape (or any other thick tape) to securely cover all sharpe edges.
Another option is to have your worn blade sharpened either at your local fabric store or by purchasing rotary blade sharpening tools yourself. Again, exercise extra caution are you switch out or sharpen rotary blades.