Double Breasted Notched Lapel Blazer

Double-Breasted Blazer with Double Welt Pockets with Flaps and Double Back Vents

Introducing jacket pattern for the double-breasted blazer with peaked lapels – Classic Tailoring with Modern Precision.

When To Wear

This jacket delivers timeless elegance and structured style, making it ideal for:

• Business & Formal Events: a polished layer over shirts or fine knits for meetings and evening occasions.
• Seasonal Outerwear: Works as a smart top layer in cooler weather when sewn in wool suiting.
• Stylish Everyday Looks: Pair with tailored trousers or dark denim for a refined casual outfit.

Key Design Features

Silhouette: Semi-fitted jacket with front and back shaping for a clean, tailored line.

Front: Double-breasted closure with peaked lapels, chest welt pocket, and two double-welt pockets with flaps.

Back: Center-back seam and double vents for comfort and movement.

Sleeves: Two-piece sleeves finished with functional button vents.

Level Of Difficulty

Advanced. Precision is required for constructing the lapel, setting tailored sleeves, and achieving a professional finish with interfacing.

Fabric Recommendations

Medium- to heavy-weight fabrics that maintain structure and drape:

• Wool suiting or tweed
• Wool-blend coatings
• Cotton twill or gabardine

For lining, choose Bemberg (cupro), silk satin, acetate, or quality polyester for a smooth interior finish.

Additional Supplies

• Fusible interfacing
• Four front buttons for the double-breasted closure
• Eight small buttons for sleeve vents
• Quality jacket lining

Cutter’s Must

From Main Fabric:

1. Back – 2 pieces
2. Front – 2 pieces
3. Side – 2 pieces
4. Upper Sleeve – 2 pieces
5. Lower Sleeve – 2 pieces
6. Collar – 2 pieces
7. Center Front Facing – 2 pieces
8. Flap – 2 pieces
9. Chest Welt (marked on pattern as “Off-set Welt”)– 1 piece
10. Upper Pocket Bag – 1 piece
11. Pocket Facing (lower pockets’ welts) – 4 pieces
12. Lower Pocket Bag – 2 pieces

From Lining Fabric:

Use main pattern pieces with the following modifications:

1. Back Lining – use Back pattern, add 2 cm pleat at center back, exclude vent extensions; cut 2.
2. Front Lining – use Front pattern excluding central front facing area; cut 2.
3. Upper Sleeve – use pattern excluding vent extension; cut 2.
4. Lower Sleeve – use pattern excluding vent extension; cut 2.
5. Flap – use pattern, cut 2.
6. Upper Pocket Bag – use pattern, cut 1.
7. Lower Pocket Bag – use pattern, cut 2.
8. Shorten both jacket and sleeve linings by 2 cm at hem.

From Fusible Interfacing:

1. Front – 2 pieces
2. Center Front Facing – 2 pieces
3. Collar - 2 pieces
4. Flap – 2 pieces
5. Chest Welt - 1 piece
6. Hem allowances of Fronts, Back, Sleeves and Vents.

Important Information

Before cutting your fabric:

• Print and lay out pattern pieces to determine yardage.
• Check mirrored pieces, notches, and grainlines.
• For patterned fabrics, align carefully for symmetry.

Assembly Instructions

1. Preparation

Apply fusible interfacing to the wrong side of Fronts, Center Front Facings, both collars, Chest Welt, Flaps, hem allowances of body and sleeves, and vent extensions.

Body Shaping

• Slash pocket opening on the front, stitch dart, cut along fold, and press open.
• Baste along pocket opening edges.

Pocket Flaps

• With right sides together, stitch each Flap to its lining.
• Turn right side out and press.

Chest Welt Pocket

On the Left Front, construct a single-welt breast pocket:

• Fold welt lengthwise, right sides together. Stitch short ends, trim corners, turn, and press.
• Place welt face down along pocket marking.
• Layer pocket bag (lining fabric) over welt, and main fabric pocket lining above, facing upward.
• Stitch 5 mm on each side of marking.
• Slash between stitching, clip diagonally to corners, turn to inside.
• Zigzag or hand-stitch welt’s free edge to lining pocket bag.
• Align pocket bags, stitch around contour.
• From right side, secure welt ends to garment.

Front Panel Seams

Stitch front panel seam; press allowances open.

Double-Welt Pockets with Flaps

Construct double-welt pockets with flaps:

• Press welts lengthwise, wrong sides together.
• Pin upper and lower welts to Front along markings.
• Place lining pocket bag on lower welt; place main pocket bag on upper welt with flap inserted between upper welt and bag (flap turned upward).
• Stitch 5 mm from each side of marking.
• Cut opening through center, clip to corners.
• Turn pocket bags inside, roll welts to form 1 cm lips, press.
• Press flap down over opening.
• Zigzag welt edges to pocket bags.
• Align and stitch pocket bags together.
• From wrong side, secure welt ends to small fabric triangles.

Body Assembly

• Stitch Backs together at center seam. Press open.
• Join shoulder seams.
• Attach Sides to Backs up to vents; press allowances open.

Collar & Facings

Attach lower collar to jacket:

• With right sides together, pin lower collar to neckline.
• Stitch neckline, clip curves, press seam allowances down.

Attach upper collar to facings:

• Stitch upper collar to center front facings along neckline; press seams open.

Join Facings to Jacket:

• Place center front facings + upper collar right sides together with jacket.
• Stitch continuously: hem → lapel → collar → opposite side.
• Trim, grade, and notch where needed.
• Turn right side out and press collar/lapels flat.

Sleeves – Two-Piece with Vent

• Stitch Upper and Lower Sleeve together to vent notch, easing as necessary; press open.
• Turn sleeve right side out.
• Fold vent and hem allowances to right side, stitch diagonal across vent corner for clean miter, trim to 1 cm, press open.
• Turn allowances inside, secure with cross-stitch, form vent overlap.

Sleeve Cap

• Ease-stitch between notches, pull threads to fit armhole.
• Steam-shrink fullness.
• Stitch sleeve seam, press open.
• Set sleeves into armholes, sewing from sleeve side.
• Fold padding (if used) and hand-stitch to sleeve caps.

Vents & Hems

• Fold back vent facing to right side; stitch along hem foldline.
• Turn right side out, slipstitch invisibly along edge.
• Fold hem allowance of side panel to right side; stitch along vent facing edge.
• Turn right side out, slipstitch invisibly.
• Lay vents toward back; secure at top with a short diagonal tack.

Shoulder Pads

Sew in shoulder pads.

Lining

• Form movement pleat at center back; secure below neckline and a few centimeters above hem.
• Assemble lining same as main garment, leaving 20 cm opening in one sleeve seam.
• Insert lining into garment, right sides together, aligning center back and shoulders.
• Stitch lining to facings and neckline edges.
• Turn upper collar edge under; press.
• Place upper and lower collars wrong sides together; hand-stitch lower collar to upper collar and back neckline with loose zigzag.
• Form jump pleat along hem; attach lining to hem allowance, stitching to right vent fold and left vent facing edge (make a small horizontal snip at base of left back vent in lining before attaching).
• Turn right side out through sleeve opening; close opening neatly.

Finishing

• Work buttonholes on left front and lapel as marked; attach buttons.
• Work non-cut decorative buttonholes on sleeves; secure vents with buttons.