Bombolini Cooler Bag Recipe

Cut pieces

Cut outer fabric: two 14 x 12 inch (35 x 30 cm) rectangles for front/back, two 4 x 12 inch (10 x 30 cm) rectangles for sides, one 14 x 4 inch (35 x 10 cm) rectangle for bottom, and one 14 x 6 inch (35 x 15 cm) rectangle for the front flap/zipper band if desired. Cut matching pieces from insulated foam and waterproof lining. Cut a 12 x 8 inch (30 x 20 cm) rectangle for an inside pocket from lining fabric.

Prepare zipper panel (if using a top zipper)

Trim the zipper to length if needed (leave 1–1.5 cm overlap at each end). Fuse or baste insulated foam to the underside of the outer fabric zipper strip and the waterproof lining to the inner zipper strip so the zipper is sandwiched between outer fabric and inner lining with insulation between.

Assemble pocket

Fold the pocket rectangle in half, right sides together, and sew the sides with a 1 cm seam. Turn right side out and press. If using a hook-and-loop closure, sew one half to the pocket flap and the mating half to the bag interior placement. Baste the pocket to the inside of one inner lining rectangle, 2 inches (5 cm) down from the top edge.

Attach zipper to panels

With right sides facing, align outer fabric top edge to zipper tape and sew using a zipper foot. Repeat with the lining piece on the other side of the zipper so the zipper is sandwiched between outer and inner layers. Press seams toward the fabric.

Sew outer shell and lining

Stack the outer shell pieces right sides together (front, side panels and bottom) and sew around the perimeter with a 1 cm seam allowance, leaving the top open. Repeat with the waterproof lining and insulated foam sandwiched inside the lining pieces (if foam is separate, baste it to the inside of the lining first).

Create box corners

To give the bag a flat bottom, pinch each bottom corner so the side and bottom seams align, measure 1.5–2 inches (4–5 cm) from the corner point, mark and sew across. Trim off the excess corner.

Attach handles

Cut webbing into two equal lengths (about 40–45 cm each for shoulder/hand carry). Fold ends under 1 cm and stitch to the outer shell front and back, 3–4 cm in from the sides. Reinforce with a box stitch or X pattern.

Combine shell and lining with zipper

Turn the outer shell right side out and keep the lining inside-out. Insert the outer shell into the lining (right sides facing each other) so zipper edges meet. Pin zipper edge and sew around the top connecting outer and lining panels. Turn bag right side out through the zipper opening. Push the lining into the bag and press the top edge.

Insert bottom support

Cut foam board or cardboard to fit the interior bottom and cover it with waterproof lining if desired. Insert into the bag bottom pocket or simply place it inside to give structure.

Finish edges

Topstitch around the top edge 3–5 mm from the seam for a clean finish. Sew any remaining binding or bias tape over raw edges. Add fabric glue to secure any loose insulation edges if needed and hand-stitch any small openings closed.

Throughout construction, use pins or clips to hold layers together. Use the zipper foot when sewing near the zipper. Press seams flat with an iron after each major seam to ensure a crisp finish. Use heavy-duty thread and reinforce high-stress points (handle attachments, zipper ends) with backstitching or box/X stitches.

Trim threads, check zipper operation, and inspect interior lining for any gaps where insulation might escape. If packaging as merchandise, add a hang tag, brand label, or care instructions: machine wash gentle cold for outer canvas, wipe interior with mild soap and water; do not soak insulated lining.