At least 3 times a week, I would pack hot lunch for the girl to bring to school. The previous lunchbox warmer that we used is just a double layers insulated cloth sheet. Though it does serve the purpose of retaining the warmth of the lunch, but I thought it isn’t as convenient since I have to wrap the bento box with the cloth manually. So, I made this warmer bag instead, using home deco fabric (thicker), thermal bubble sheet (from Daiso) and assorted color felts for the ninja pattern.
If you are keen to make one yourself and need a tutorial to guide you, here’s one I found on pinterest that is closest to how I made mine.