Introduction: DIY Insulated Backpack


As a college student, we utilize all free amenities and deals we can get. However from this, we obtain a lot of stuff that we no longer need or want. I decided to upcycle old t-shirts, old fleece, and an insulated bag into a backpack.

It is designed to be a small backpack for picnics or lunch bag for school and work. I made the lining of the insulated bag for easy maintenance and upkeep. It is meant for everyday use.

Step 1: Step 1: Gather Materials

Gather all materials and make sure everything is usable. If fleece pieces have holes in it, either patch it up or try to find another piece.

A list of the items are:

  • 1 medium sized cotton t-shirt
  • Large scrap pieces of Fleece
  • 8.5” x11” sheet of plastic
  • Scissors
  • Rope (not shown in images)
  • Insulated bag
  • Hot glue gun
  • Velcro
  • Industrial Sewing Machine
  • Sewing Needles
  • Thread

Step 2: Step 2: Build the Base

We are going to build the base of the backpack first. Cut out 6”x10” piece of the plastic sheet. To wrap the plastic, cut out two pieces of fleece that is 8”x 12” and sew around the fleece to plastic the sheet inside of the fleece. I left extra room to give space for the other parts of the backpack be connected

Step 3: Step 3: Build the Body

For the body of the backpack, I took apart the t-shirt and cut out two 7”x13” pieces of cotton. I then cut out 11”x13” piece of cotton fabric. Using the four pieces of cotton fabric, I placed them on top of the fleece material as a stencil to cut out. Sew all four sides of the fleece to close them.

Step 4: Step 4: Making the Straps

Let’s make the straps next! I cut out 2 strips of 24”x 1.5” of the insulated bag material. It is used as a cushion. To wrap the handles, I cut out two 6”x26” of fleece. I sewed one edge to create a cover for the straps. Turn the covers inside out.I placed the straps inside.

Step 5: Step 5: Adding the Straps

I placed 3 inches of the strap onto one of the 11”x13” piece of cotton/ fleece fabrics. On the cotton side, I placed my straps 3 inches from the top. I then folded the straps about 3 inches inward. I then sewed the straps onto the fleece to secure it. I sewed the top and the bottom for both straps.

Step 6: Step 6: Making the Cover

I cut out two pieces of 7”x 13”of fleece. I sewed the bag on three ends and then flipped it inside out to sew it shut.

Step 7: Step 7: Construction of the Body

I sewed all four sides together first. Make sure you sew on the fleece side to allow the cotton side to look cleaner.

Step 8: Step 8: Creating the Drawstring Area

Fold an inch down from the bag and sew straight across to create a tunnel for the rope. Cut a hole in the front to allow the string to come out. I cut off a 24” long piece of rope for the bag.

Step 9: Step 9: Connecting the Bag to Base

Connect all four sides to the base. Make sure the sewing seam is on the inside of the bag

Step 10: Step 10: Adding the Cover

Sew the cover of the bag on the back of the fleece part of the backpack. Because the area is very thick, you may need to hand sew the cover onto the bag.

Step 11: Step 11: Adding the Handles

I cut out a piece of fleece 4”x10”. I folded the piece of fleece on to make it 4.5”x13’. I then sewed it together and flipped it inside out. On the cotton side of the backpack, add the handles of the backpack. Make sure to not sew where the rope overlaps.

Step 12: Step 12: Pieces of the Insulated Bag

For the insulated bag, I cut out two 6”x12”, two 10”x12”, one 6”x10” pieces of the insulating material.

Step 13: Step 13: Creating the Shape of the Insulated Bag

Because this material is a bit sensitive, I first hot glued the bag together to know where to sew

Step 14: Step 14: Constructing the Insulated Bag

Step 15: Step 15: Adding Velcro

I then added velcro on four sides of the fleece side of the bag and added the corresponding piece to insulated bag. The velcro adding varies on the brand. The velcro I purchased was iron on

Step 16: Step 16: Finish Touches

I placed the insulated bag into the backpack and it is now complete

Step 17: Wrap Up

I wish that I made the bag bigger. I think that the bag is a good size for a child, less for an adult. I think the straps in particular, have to be a lot longer to make it easier to put on and off.