A round brim will not be of equal width all around from headsize wire, because the headsize wire must be oval to fit the head. The front and back will both be about an inch narrower than the sides.
Headsize wire—
To measure—This is especially important, for upon the accuracy of this measurement depends the comfort of the wearer; this is the foundation wire. Pass a tape measure around the head over the hair where the hat is to rest and add two inches to this measure. One is for lapping the ends and the other inch is to allow for lining and covering of hat which goes up into the headsize.[7-1]
As our headsize measure is twenty-four inches long, cut a piece of frame wire twenty-six inches long; this allows for the two inches just mentioned. Lap the ends one inch and fasten each end with tie wire.[7-2] Wire always laps one inch—no more, no less.
To shape—With the hands inside, pull the circle until it is elongated to fit the head. This headsize wire must not press unduly upon any part of the head.
To locate headsize on pattern—Lay pattern flat, pin headsize wire on pattern with joining at back crease in paper, having the back and front of brim of equal width, and the two sides of brim of equal width. Mark all around headsize wire with a pencil. Remove wire and cut paper one-half inch inside this mark.
To cut buckram brim—Lay pattern on smooth side of buckram, pin, and cut the edges very smoothly. Cut headsize same as pattern. Mark location of center back and center front. Remove pattern and with a hot iron press the buckram perfectly flat, being careful not to break or make a sharp bend in the buckram, for if once broken it cannot be satisfactorily repaired.
To sew headsize wire to brim—First note the relation of headsize wire to brim. If buckram is carefully cut, the wire may be pinned on one-half inch from edge. The brim has been cut round and will have the appearance of a round hat when worn and yet, on account of the oval headsize wire, the brim when finished will measure about three and one-half inches on each side and about two and one-half inches back and front. Pin wire on smooth side of buckram with lap at center back, also pin front and each side, being careful not to lose the shape of the headsize wire. Bring needle up from under side of brim close to wire, beginning at lap. Take stitch over wire to under side coming back through first stitch to right side. Take next stitch over wire one-fourth inch from first, coming back to right side. Repeat all the way around until lap is reached. Fasten thread by taking several stitches close together over ends of wire in order to join neatly and prevent their working loose. Slash buckram inside headsize wire every half inch and turn pieces up. This makes small flaps to which crown may be fastened later. The brim may now be tried on and changes made if necessary.
Edge wire—
This is cut from frame wire and must be long enough to reach around edge of brim and lap one inch. Edge wire is always sewed on same side of brim as the headsize wire, which is usually the smooth side. Shape this wire to conform to shape of brim. Never depend on the hat or the stitches to hold a wire in place. Begin at center-back of hat holding wire toward you, and sewing from right to left. Hold wire as near the edge as possible, without letting it slip over the edge. Sew on with overcasting stitch, taking two stitches in same hole. Take the stitches just the depth of the wire. If too shallow, the wire will slip off over the edge, or, if too deep, the wire will slip back away from the edge leaving it unprotected and liable to become broken and uneven-looking. A frame must be well made in every detail to produce satisfactory results when finished.