Asymmetrical Sling Bag

 

The Asymmetrical Sling is a dynamic, modern carry-all designed for the fluid motion of city life. Its striking diagonal silhouette hugs the body effortlessly, offering ergonomic comfort whether worn across the back or the chest. With its subtle lean and architectural lines, this bag merges minimalist structure with maximum utility—a sophisticated companion for commuters, creatives, and urban explorers alike.

Part 2: Fabric Recommendations & Required Materials

For a functional, durable, and professional-looking sling bag, choose fabrics that offer structure and resistance to wear.

Fabrics:

• Exterior Shell (Structured): Canvas (10-14oz), Duck Cloth, Cordura, waxed canvas, heavy upholstery fabric, or lightweight leather/vinyl.
  
• Lining (Smooth): Cotton quilting fabric, nylon ripstop, polyester lining, or chambray.
  
• Interfacing (Crucial):
  
• For structured fabrics (e.g., heavy canvas): Medium-weight fusible woven interfacing (like SF101) for the main body panels.
  
• For softer fabrics: Fusible fleece (like 987F) for padding and body.
  

Required Materials (Hardware & Notions):

• Fabrics:
  
• Exterior: 1/2 yard (or a fat quarter if careful with layout)
  
• Lining: 1/2 yard
  
• Interfacing (Fusible Woven): 1 yard
  
• Zipper: One 12-inch (30 cm) heavy-duty zipper (e.g., #5 metal or coil).
  
• Webbing (Strap): 1.5 yards of 1.5-inch (38mm) nylon or cotton webbing.
  
• Hardware (Matching 1.5" width):
  
• One 1.5-inch Rectangle Ring or D-ring.
  
• One 1.5-inch Adjustable Slider buckle.
  
• One 1.5-inch Swivel Snap Hook (optional, but convenient).
  

Part 3: Medium Asymmetrical Sling Measurements

This bag is sized to hold a standard 10-inch tablet, a water bottle, a small notebook, and daily essentials.

• Total Height (at peak): 15 inches (38 cm)
  
• Width (at widest point): 9 inches (23 cm)
  
• Depth (Side Gusset): 3 inches (7.5 cm)
  

Part 4: Step-by-Step Pattern Drafting

We will draft the asymmetrical shape directly. For a medium bag, start with a grid on paper. Use a large ruler.

Drafting scale: 1 grid square = 1 inch.

1. Draft the Main Body Panel (Front & Back)

(Create one full pattern piece for the body. You will cut two from fabric.)

1. Drafting Base: Create a grid rectangle 9" wide by 15" tall.
   
2. Define Asymmetry (Height):
   
• Mark the Top-Left (Peak) corner at 15" height.
  
• Mark the Top-Right corner at 13" height (a 2" diagonal drop).
  
3. Define Asymmetry (Width):
   
• Mark the Bottom-Left corner at 0" width, 0" height.
  
• Mark the Bottom-Right corner at 9" width, 0" height.
  
• Create the diagonal top line: Connect the peak (15" height, 0" width) to the right point (13" height, 9" width).
  
• Curve Option: To make it less rigid, softly curve the two bottom corners and the diagonal peak. Use a plate or a French curve ruler.
  
4. Add Seam Allowance: Draw a uniform 1/2-inch (1.25 cm) border around the entire drafted shape. Label this "MAIN BODY (Cut 2 Interior, Cut 2 Exterior, Cut 4 Interfacing)".
   

2. Draft the Bottom Gusset (Base)

This piece joins the front and back body panels.

1. Dimensions: Draw a rectangle 9" wide by 4" tall.
   
2. Seam Allowance: Add 1/2-inch to all four sides. Total size: 10" x 5". Label "BOTTOM GUSSET (Cut 1 Ext, Cut 1 Int, Cut 2 Interfacing)".
   

3. Draft the Side Gusset (Gusset Panels)

These panels wrap the sides and define the bag’s depth.

1. Left Side Gusset: This panel runs from the peak to the bottom corner.
   
• Measure the left side length of your drafted main panel (roughly 14"). Draw a rectangle 14" tall by 4" wide.
  
2. Right Side Gusset: This panel runs from the 13" point to the bottom corner.
   
• Draw a rectangle 12" tall by 4" wide.
  
3. Add Seam Allowance: Add 1/2-inch to all four sides of both side gussets. Label "LEFT/RIGHT SIDE GUSSET (Cut 1 each, Ext/Int/Intfc)".
   

Part 5: Complete Bag Pieces & Seam Allowances

All Seam Allowances are 1/2 inch (1.25 cm) unless stated otherwise.

Exterior Pieces:

• [1] Main Body Front
  
• [1] Main Body Back
  
• [1] Bottom Gusset
  
• [1] Left Side Gusset
  
• [1] Right Side Gusset
  

Lining Pieces:

• [2] Main Body Panels
  
• [1] Bottom Gusset
  
• [1] Left Side Gusset
  
• [1] Right Side Gusset
  
• [(Optional) 1] Internal Zipper Pocket (Rectangle 9" x 7")
  

Interfacing Pieces:

• [4] Main Body Panels
  
• [2] Bottom Gusset
  
• [2] Side Gusset Panels
  

Part 6: Methods and Instructions (How to Make It)

Phase 1: Preparation and Interfacing

1. Cut all fabric and interfacing pieces.
   
2. Fuse the interfacing to the wrong side of all corresponding exterior fabric pieces following the manufacturer’s instructions. (Also fuse interfacing to two lining panels if the lining is very light).
   

Phase 2: Constructing the Strap Assembly

1. Strap Connector (D-Ring Loop): Cut a 4" piece of webbing. Slide the rectangle ring (or D-ring) onto the centre. Fold the webbing in half and baste the raw ends together.
   
2. Adjustable Strap: Cut the remaining 1.5 yards of webbing. Slide one end through the adjustable slider, creating a small loop (about 2"). Stitch this loop down with two lines of reinforcing stitches (a box-X).
   
3. Prepare the Exterior Back: Take the Exterior Back panel. On the lower right curve, pin the basted raw edge of the Strap Connector (D-Ring Loop) within the seam allowance.
   
4. Pin Strap Top: Pin the long webbing strap raw end to the left side peak within the seam allowance, ensuring the slider is facing the back of the bag and the strap lies flat. Baste both connector points to secure.
   

Phase 3: Exterior Construction

1. Assemble the Gusset: Take the Bottom Gusset and the Left Side Gusset. Align them RST (Right Sides Together) on the narrow 4" edge. Stitch. Repeat with the Right Side Gusset. You now have a long U-shaped gusset strip. Press seams open.
   
2. Attach Gusset to Front: Pin the continuous gusset strip RST around the perimeter of the Front Main Panel, matching corners. Take time to clip curves if needed to allow the gusset to lie flat. Stitch around the entire U-shape.
   
3. Attach Gusset to Back: Repeat Step 2 to attach the raw edge of the gusset to the back Main Panel (which has the strap connector and top strap basted to it). Ensure the top strap peak aligns correctly with the gusset flow.
   
4. Turn the exterior bag right side out and check structure.
   

Phase 4: Lining Construction & Installation

1. (Optional) Create and insert an interior zipper pocket into one lining body panel.
   
2. Assemble Lining Gusset: Repeat Step 1 of Exterior Construction, using lining pieces. Crucial: Leave a 6-inch (15 cm) opening unstitched in one side of the lining gusset. This is for turning the bag later.
   
3. Construct Lining U-shape: Repeat Steps 2 and 3 of Exterior Construction using lining panels to create a lining "bag."
   
4. Prepare for Joining: Keep the exterior bag turned right side out. Keep the lining bag turned wrong side out.
   

Phase 5: Inserting the Main Zipper

1. Slide the lining bag inside the exterior bag (RST). The strap and hardware will be sandwiched between the two bags.
   
2. Match the top raw edges of the diagonal peak and sides, centring the strap connector and strap.
   
3. Insert the main 12" zipper between the exterior peak and the lining peak. The zipper pull should face the peak. Align the raw edges and the zipper tape teeth. Stitch using a zipper foot, securing the zipper through all layers (exterior, zipper tape, lining).
   
4. Secure the rest of the top opening circumference, matching lining and exterior raw edges and stitching with a 1/2" seam allowance. Stitch carefully over the strap and connector attachments, reversing several times for strength.
   

Phase 6: Turning and Finishing

1. Pull the entire exterior bag through the opening left in the lining gusset. This is sometimes called "birthing the bag."
   
2. Ensure all corners are pushed out smoothly.
   
3. Press the lining opening raw edges inward by 1/4 inch and topstitch the lining opening closed by machine. Push the lining down into the bag.
   
4. Topstitch around the zipper opening edge (about 1/8 inch from the edge) for a professional finish and to keep the lining from catching in the zipper.
   

Part 7: Tips for Sewing a Beautiful Bag

• Zipper Foot: Always use a zipper foot when sewing the main zipper and pockets. It allows you to get close to the zipper coils without distorting the fabric.
  
• Woven Interfacing: Do not skip the interfacing! Woven fusible (SF101 style) gives body and crisp structure to your fabric, prevent sagging, and strengthens seams without making the bag stiff.
  
• Clipping Curves: When sewing curves (like the bottom corners), make small V-notch clips in the seam allowance after stitching but before turning. This helps the fabric lie flat on the outside.
  
• Stitch Strength: For strap connections (D-rings and webbing attached to the bag body), reinforce the attachment points. Sew a "Box-X" stitch (a square with an X across it) using heavy-duty thread to distribute the weight load.
  
• Hump Jumper (Clearance Plate): When sewing thick layers (like joining canvas/webbing seams), use a hump jumper tool or a folded piece of cardboard under the back of the presser foot to keep the foot level.