The F CLEF is a sign placed at the beginning of the music staff to indicate the pitches of the notes. Without a clef sign, notes on a staff have no meaning. It is the key that leads to being able to read the music.
The F clef is also called the bass clef, and some even call it the "left" clef because it usually indicates what the left hand is doing in piano music (but not always...).
When drawing this clef, the upper curve curls around the fourth line of the staff, which indicates the F below middle C. Two dots are placed above and below the same line for emphasis.
Digital downloads of each pattern purchased consist of seven pages (8.5 x 11 inches), including four pages which when trimmed and taped together make the full-size (15 inches square) pattern master for doing the applique or embroidery method of your choosing. The download is in Adobe PDF format and you will need the free Adobe Reader software to print the pages.