Yes, you can pin, but sewing clips ...
- are fast and painless
- can hold a lot of fabric layers without distortion
- are not too big, they don't get in the way when sewing
- have have flat backs and flat sides - whatever you hold is held flat so that the hem or edge doesn't pucker or wrinkle up
- are easy to find when you drop them on the floor
- are a great alternative to sewing pins on projects where you don't want pinholes in your fabric (laminate, leather, vinyl, silk, satin, ...)
- have line markings on the bottom to help you place your clips
- are also loved by quilters for clipping binding in place when preparing to sew it up
- are also referred to as hemming clips or wonder clips
If you haven’t used them, you must! They will come in handy for so many things related to needlework.