How to Sew a Messenger Style Field Bag – Free Step-by-Step Tutorial

Perfect for school, college, or day trips!

Learn how to sew this roomy field bag with our free step-by-step tutorial—no printed pattern pieces required. This bag is practical and durable. Milo used theirs all last year at college, and it carried everything from a laptop to notebooks and supplies for class.

The field bag is fully lined, so there are no raw edges inside. For sturdiness, I recommend a heavier outer fabric such as twill, denim, or duck cloth. The lining and flap are made with cotton fabric, giving you plenty of options to customize. I added machine embroidery to the front of my bag, but you could leave it plain, sew on patches, or get creative with other embellishments.

The finished bag measures 5" deep and includes a handy hanging pocket inside. A wide, adjustable webbing strap makes it comfortable to carry, and large buckles keep everything secure.

Keep reading for the full sewing tutorial—or watch the video version through the link below.

WHAT YOU NEED to make a field bag

• 1 yard fabric – Main Fabric - Denim, Twill, duck cloth or other heavy fabric
• 1 yard fabric - Lining Fabric – Cotton Print
• ¼ yard - Hanging Pocket Fabric – Cotton Print

For Strap & Buckles

• 2 – 1” Parachute Buckles
• 2 – 2” rectangle strap hardware
• 1 – 2” rectangle strap slide
• 2 yards - 2” wide Strap Webbing Fabric (for the strap)
• 1 yard – 1” wide strap webbing (for attaching parachute buckles)

For Optional Hanging Pocket

• 7” zipper 

Other Supplies

• Standard sewing supplies: Pins, Scissors, Iron, Ironing Board, Sewing Machine
• Rotary Cutter, Rulers & Mat (optional)
• Lighter or Fray Check for sealing the cut edges of the webbing
• Letter Pins, AlphaClippies or masking tape & marker

Cutting Instructions For Bag, Lining, and Flap

I recommend using letter pins or AlphaClippies to label the cut fabric pieces.  A piece of masking tape with the letters written on it will also work. These letter labels will be referred to throughout this tutorial.

There are some missing letters; this is intentional.

Main Fabric Cut:

• A - Front Flap – Cut 1 – 12 1/2” x 16”
• B - Front & Back – Cut 2 – 12 1/2” x 16”
• C - Gusset – 42” x 5” (Gusset can be cut < 5" to adjust the depth of the bag. Add 1" for seam allowances to the depth needed. Cut the same width for Lining Gusset (I).)
• D - Flap Cover – 2 ¼” x 12 1/2”

Lining Fabric Cut:

• G - Front Flap Lining – Cut 1 – 12 1/2” x 16”
• H - Front & Back – Cut 2 – 12 1/2” x 16”
• I - Gusset – Cut 1 – 42” x 5” (Gusset can be cut < 5" to adjust the depth of the bag. Add 1" for seam allowances to the depth needed. Cut the same width as Outer Gusset (C).)

Hanging Pocket Fabric:

• O - Cut 1 – 7” x 14”
• P - Cut 1 – 7” x 2 ¼”

General Pattern Directions:

• Seam Allowance: 1/4” unless otherwise specified.  Use a straight stitch at normal length unless otherwise specified
• Needle: Use a Jeans Needle or 90/14 needle
• Difficulty: Confident Beginner
• Time: Approximately 3 - 5 hours.

Prepare Straps and Accessories

Before starting construction of the bag, prepare the straps, buckles, and hanging pocket.  Set these aside for use in future steps.

Step 1: Prepare Parachute Buckles

Cut from the 1" webbing:

• Cut 2 – 6” lengths
• Cut 2 – 12” lengths 

Use a lighter or fray check to seal the cut edges of the strap fabric.  This strapping will fray easily, so it's important to seal any cut edges.  I prefer to use a lighter as it melts the edge nicely.

Thread the two 6" lengths of webbing onto each female buckle. Line up the ends of the webbing so they are even.

Use a zipper foot and stitch the webbing together close to the buckle. Stitch back and forth two times.

Thread the 12” pieces of webbing onto the male buckle. Leave one long end to use to attach to the bag.

To keep the buckle from slipping off the strap, fold the strap end under and stitch it. Fold the end of the flap strap coming off the back of the buckle under ½” two or three times to make a thicker end of the strap. Stitch across the folds to hold them in place. This will give the lip, making it harder for the buckle to slide off the end of the strap.

Step 2: Prepare 2" Rectangle Strap Hardware

Cut two 3” pieces of the 2” webbing.  The remainder of the webbing will be used for the bag strap. Use a lighter or fray check to seal the cut edges of the strap fabric so they won't fray.

Thread each piece of webbing through the 2" rectangle hardware and fold it in half. 

Using a zipper foot, stitch the webbing close to the strap hardware. These rectangular hardware pieces can rotate while using the bag; stitching it will help prevent this rotation as the bag is used.  Stitch across and back twice.

Step 3: Prepare Hanging Zipper Pocket

Put a zipper foot on your sewing machine.

Place the long edge of the smaller piece of fabric (P) along one side of the zipper with right sides facing together. Place the fabric so that the end of the zipper is at least ¼” inside the edge or outside the edge of the fabric.

Stitch a straight stitch close to the zipper. Finger-press the seam open.

Stitch the longer piece (O) onto the other side of the zipper with right sides together. Align the edges of the fabric along the sides.

Finger-press the fabric open along the zipper.

Fold the length in half with right sides together so the short raw edges align at the top.

Pin the two sides, moving the zipper pull to the center so you won’t hit it when sewing the sides.

Stitch with a ¼” seam allowance along the two sides. Be careful when stitching over the zipper to avoid hitting any metal parts.

Trim off the zipper where it extends past the edges.

Zig-zag or overlock to finish the two long edges of the bag.

Turn the bag right side out through the top opening and press nicely.

Finally, zig-zag or overlock finish the top short edge of the bag.

Prepare Pieces for Bag Assembly

Step 4: Curve Bottom Corners

Curve the bottom corners of the pieces: A, B, G, and H. Use a plate, CD/DVD, or other curved item to make a curve on the corners. The curves will be at the bottom of the bag.

Lay the three lining pieces (G & H) on top of one another.  Place your curved item in the corner and use a pencil to trace a line to mark the first corner.  Cut along the line to create the corner curve.

Fold the fabric in half along the shorter side.  Trace and cut the 2^nd corner. 

Lay the curved lining fabric on top of the three main fabric pieces (A & B). Trace and cut the same curves onto the outer fabric pieces.

BAG Assembly

Step 5: Flap Cover (D)

Prepare the Flap Cover (D). Fold the two long edges (12” edge) towards the wrong side of the fabric by ¼” and press to crease.

Lay the Main BACK Piece (B) with the right side up on a work surface. Place the flap cover (D) across the back piece with the wrong side facing down, 1 ½” from the squared short edge (top of bag).

 Pin in place.

Stitch three sides. Stitch the short sides with ¼” seam allowance (so it won't show on the outside of the bag later). Topstitch along the folded edge closer to the curved edge of the bag.  Do not stitch the long side closer to the top of the bag; we will put the flap here later.

Step 6: Add Parachute Buckles to Bag Front (B)

Lay the Main FRONT piece (B) on a work surface. Place the two MALE parachute buckles (one with a longer strap) onto the bag front, 2” from the bottom of the bag (curved edge) and 2 ½” from the sides. Measure from the side of the bag fabric to the side/end of the strap.

Pin the straps in place.  Take a small 2" x 2" piece of scrap outer fabric or interfacing and place it under the end of the strap on the wrong side of the fabric. This will give extra support to the straps during use.

Stitch the strap and extra fabric to the bag using a 1” box with an X in the middle.

Pin the straps out of the way.

Step 7: Sew Gusset (C) onto Bag Back & Front (B)

Pin Gusset (C) to the BACK (B) piece with RIGHT SIDES together. Start at one of the squared corners. Pin down the side towards the bottom curved edge.  Pin around the curve, across the bottom, and around the other curve. End at the top edge. 

There will probably be extra gusset fabric.  Cut off the extra gusset fabric.

NOTE: The gusset has extra length because the type of curve you cut will require more or less gusset fabric, so I added extra length to ensure you have enough.

Sew around the edge with a 1/2” seam allowance with a straight stitch at the normal stitch length. If using canvas or jeans fabric, use a Jeans needle or at minimum a 90/14 needle.

To reinforce the seam, sew a 2^nd line of stitching inside the seam allowance 1/8” from the first seam.

Pin and sew the other side of the gusset to the FRONT (B) in a similar manner with two lines of stitching.

Step 8: Bag Lining Assembly

Sew the lining gusset (I) to the back lining (H) like the outside bag. Pin the gusset to the bag back, aligning the raw edges, and stitch with a ½” seam allowance. Trim off the extra gusset.

Sew the front lining (H) to the gusset in the same way. Leave a 5" opening in the seam along the bottom edge for turning the bag.

I like to put two pins at the beginning and end of the opening to mark the opening.  This reminds me to stop stitching and leave the opening in the fabric.

Step 9: Insert the Lining into the Bag

Turn the lining right side out. Place the lining into the bag. Match up the seams on each corner.

Place the hanging zipper pocket on the back side of the bag, centered.  The back of the bag has a flap cover.  Face the zipper of the hanging pocket towards the main bag fabric. 

Pin/clip around the top of the bag.

Stitch around the top of the bag with a 1/2” seam to hold the lining and hanging zipper pocket in place.

Turn the bag right side out through the opening in the lining.

Next, stitch the lining opening closed. Fold the seam to the inside, iron, and pin.

Use the hand-stitched ladder stitch or a top stitch with a sewing machine to close the opening.

Since this won't be seen, I prefer to topstitch the opening closed.

Push the lining inside the bag and press along the top edge. Topstitch around the top edge of the bag. Add another line of stitching at 5/8” from the top of the bag.

Be sure you are stitching the second line of stitching at 5/8" or less. The bag flap cover is close to the edge, and you don't want to stitch it closed by mistake.

Step 10: Sew Bag Flap

If you'd like to decorate your bag flap, add those decorations to the FLAP outer fabric (A) now.  Before adding the decorations, consider where the straps will be placed so that they will not cover your embroidery (see step 11 for where the straps will be placed).

Lay Flap (A) and Flap lining (G) with RIGHT SIDES together. Stitch with a ½” seam allowance around the edge to hold them together.

Clip the corners.

Turn the flap right side out and press.

Topstitch 1/8” from the edge of the flap. Stitch a second line of stitching 1/8” from the first line of stitching.

Step 11: Add Buckles to Bag Flap

Add the FEMALE buckle with the shorter strap to the FLAP.  Measure 2" from the side of the strap to the side of the fabric.  Then measure 2 1/2” from the curved edge to the ends of the strap. 

Pin the straps in place.

Stitch a 1” box with an ‘X’ at the end of the strap.

Step 12: Sew Flap onto Bag

Next, insert the bag flap into the bag flap cover (D) on the back of the outer bag with the right side facing up.

Push the flap all the way into the flap cover.

Slide the rectangle hardware with the strap on it under the bag flap cover, one at each side.

Pin in place.

Stitch two lines of stitching across the open edge of the flap cover (D) to attach the flap to the bag. Stitch at 1/8” and 1/4”. Be careful, do not stitch the front of the bag in the seam.  It's helpful to use the sewing machine free arm for this step.

BAG STRAP

Step 13: Add the Bag Strap

Thread one end of the remaining 2" wide strap through the rectangle strap slide.

Overlap the strap by 3”. Stitch a 2” box to hold the strap together.

Thread the free end of the strap through one rectangular hardware on the bag from the back to the front.

Continue to thread the end of the strap through the rectangular strap slide.

Finally, thread the end of the strap through the other rectangle hardware from the front to the back.  Make sure the strap is not twisted.

Overlap the strap by 2 1/2” and sew a 2” box to hold the strap onto the rectangle hardware.

That completes the field bag! 

We hope you enjoyed making this field bag.  Below are some photos of the finished bag.

Some other bag projects you may be interested in are:

• T-Shirt Tote Bag - Recycle an old t-shirt into a handy tote bag.
• Bandana Drawstring Bag - This quick drawstring bag is great for kids to use during day trips to hold a water bottle & snack.
• Market Bag - Make a durable / reusable shopping bag to take grocery shopping.
• Simple Tote Bag - This quick and easy-to-make tote bag has neatly finished seams on the inside.