Sewing - Insulated Jacket
All content copyright © 2010-2018 Frank Revelo, United States copyright office registration number TX-7931345
Problems with commercial insulated jackets:
- Shell fabric lightweight and hence easily torn on thorns.
- Shell fabric not available in color I prefer.
- Embroidered logos cannot be easily removed.
- Too loose in stomach, to accomodate fatties.
- Too tight in underarms, so easily soiled by perspiration.
- Same thickness insulation everywhere, rather than heavier in torso and lighter in arms.
- Insulation typically primaloft rather than continuous fiber polyester, hence heavier for given warmth and less durable.
- Hand warmer pockets add weight and slow drying time.
Comments about design:
- Supplex draft flap weighs about 10 grams, whereas flap made with liner fabric would weigh about 5 grams. However, liner fabric more likely to catch in zipper than supplex. If liner flap faced with grosgrain, to prevent catching in zipper, weight rises to 10 grams, same as supplex, plus grosgrain adds stiffness and thus discomfort when using jacket as pillow.
- Collar will not lay flat, which makes jacket uncomfortable in warm conditions. Possibly a different design would allow collar to lay flat, but a simpler solution is to tuck collar under warm conditions.
- Possibly increase length of torso. Currently, torso 30" long, or exactly half insulation width. Thus insulation can be folded width-wise to cut double layer torso insulation. If torso length increases, possibly use single layer insulation at bottom of torso and double layer at top. For example, if length increased to 34", then bottom 8" will have single layer of insulation and top 26" of torso will have double layers. Alternatively, specify more insulation yardage in materials list, fold lengthwise before cutting, and continue to cut double layer insulation for entire torso.
- Zipper gets dirty in field use, which may shorten zipper life. May need to replace zipper more frequently than replacing entire jacket. TBC to be continued...
Weighs 470g, assuming shell 3.3 oz/sqyd supplex from SeattleFabrics.com, lining 1.0 oz/sqyd calendared HyperD diamond ripstop nylon from RipstopByTheRoll.com, insulation 2.5 oz/sqyd Climashield continuous fiber polyester from RipstopByTheRoll.com.
Similar to that of shirt, except remove about 1" from front width to accomodate zipper, different neck opening, different collar, shorter torso. TBC 2016 jacket used neck pattern from shirt versus larger neck opening in back piece of current paper jacket pattern, so probably need to make collar wider in back; also trim inch of top inside front of pattern, since jacket too wide there
- 2 yards shell fabric, at least 60" wide.
- 2 yards lining fabric, at least 60" wide.
- 3 yards insulation, at least 60" wide.
- 36" #5 separating zipper.
- 90/14 universal needles.
- 100% polyester thread.
- (optional) 3/32" shock cord.
- (optional) walking foot accessory for sewing machine.
- Single line of stitching sufficient everywhere, assuming strong thread. Single line, and no more than single line, mandatory when top-stitching to stabilize insulation.
- Walking foot recommended where noted, otherwise standard presser foot or zipper foot.
- Cut shell fabric: 1 back, 2 fronts (left and right), 2 sleeves, 2 collars, 2 draft flaps. Sear edges with candle, other than for draft flap pieces (searing creates sharp edges which catch on insulation, which will cause problems when turning draft flap inside out, due to its narrowness).
- Cut liner fabric: 1 back, 2 fronts (left and right), 2 sleeves. Sear edges with candle.
- Cut insulation: 2 back, 4 fronts, 2 sleeves, 2 collars, 1 draft flap. In all cases, insulation fibers should be aligned so they run from top to bottom of garment. Note that insulation fibers run side-to-side for continuous fiber polyester ("cross-grain" direction, if speaking of woven fabric). Trim 3/4" off bottom of insulation, to allow closing hem later.
- Back, sleeves, fronts: Sew together shell and lining, right sides facing, 3/8" seam allowance, leaving bottom open.
- Collar: Sew together, right sides facing, 3/8" seam allowance, leaving bottom open.
- Draft flap: Sew together, right sides facing, 1/4" seam allowance, leaving bottom open.
- Walking foot. Pin insulation to fabric. Single layer for sleeves and draft flap, double layer for back, front and collar. For everything except draft flap, sew insulation to fabric using zigzag in seam allowance on sides and top, plus another line of stitching attaching bottom of insulation to lining, about 1/2" from bottom edge. For draft flap, sew insulation to top edge only. Because of how insulation stretches and gets caught in sewing machine, zigzag better than straight stitch and walking foot better than standard presser foot.
- In steps below, after turning inside-out and before top-stitching, stretch edges taut and possibly pin to keep stretched. Otherwise, fabric may be caught under top-stitching.
- Back, fronts, sleeves: Turn inside-out. Top-stitch edges using 3/8" seam allowance. Close bottom with 3/8" hem, with optional tunnel in hem.
- Collar: Turn inside-out. Close bottom with 3/8" hem.
- Draft flap: Turn inside-out. Insulation will stretch and thus become thinner, but this is okay, as long as the stretching is not excessive. Trim excess insulation from bottom. Top stitch using 1/4" seam allowance, close bottom with 1/4" hem. Stabilize insulation by top-stitching across draft flap at 8" intervals.
- Double fold 1" strip of shell fabric and top-stitch. Cut 3" piece and bartack to collar seam allowance to make hanging loop.
- Attach fronts to back, and then collar to torso, using 3/8" seam allowances that were top-stitched previously.
- Attach zipper, folding to sides at top to create stop. Trim excess zipper from top.
- Attach draft flap behind left-side zipper.
- Double fold 2" wide strip of shell fabric and top stitch, to form strips 1/2" wide. Cut 3" strips, doubly fold so 3/4" long, stitch in place over top of zipper, to cover sharp edges of cut zipper coil.
- Single line of stitching (if thread breaks, seamrip and start over). Horizontally top-stitch back, fronts, sleeves at approximately 6" to 8" intervals to stabilize insulation. Remember that primary area of stress will be near shoulders, due to backpack straps, and against lower back, due to backpack bottom swinging side to side. Must perform top-stitching after installing zipper, so lines of top-stitching will match on front pieces. Matching lines of top-stitching between front and back not necessary.
- Attach sleeves to torso, using 3/8" seam allowances that were top-stitched previously.
- Sew up sides of torso and sleeves, using 3/8" seam allowances that were top-stitched previously. Optionally, leave 2" opening at armpits for ventilation.
- (Optional) Install shock cord in tunnels at bottoms of sleeves and torso. After cutting to proper length, top-stitch ends of shock cord to hold in place.