The up and down motion of the material with the needle that is caused by improper hooping, the presser foot not being properly adjusted (too much clearance with needle plate), and improper fabric stabilization (incorrect backing). Named because of its resemblance to a waving flag. Flagging generally causes improper needle loop formation that can lead to skipped stitches and thread breakage. Flagging can also negatively impact the appearance of the finished product resulting in poor design registration.