Best way to stiffen a denim bag for carrying a laptop

[AllTheChicken]

I'm making a square bag out of an old pair of jeans, but I'd like to make it sturdier to use to carry heavier bits like a laptop and maybe a book/notebook or two. I was thinking of using cardboard with the corrigated bits going in two different directions to avoid buckling but I don't want it too bulky or heavy, so is there something else I could use instead?

I’d use a plastic folder of some sort. Cut up into pieces of the right shape. There are many different levels of stiffness - a big stationery or art shop would have some options.

Cardboard isn't really practical for a bag, it will get soaked through when it rains.

Not homemade but I use an handbag insert in soft floppy bags. It’s stiff felt type material.

Or a laptop pouch? You can get them in padded fabric or neoprene type which would bring the stiffness.

can you use felt? You get bag organizers on Amazon to put into bags which are not stiff

I used plastic chopping boards from Ikea. The flexible ones? Trim to fit.

How about the thickest variety of iron on stiffening? I agree a plastic folder might be the best way to go.

Paint PVA glue on the inside? Obviously so a tester square first.

I'd spray it with ironing starch.

I would use the thick stuff felt in the bag, and also pad the inside ☺️

Ask your local dress/curtain material shop or haberdashery about Buckram.
It’s a stiffener for fabrics.

You need some interfacing. You can get it in a variety of different textures and thicknesses and it’s designed exactly for this job. A medium-weight woven fusible interfacing (like Pellon SF101 Shape-Flex) you iron it onto the back side of the outer fabric and it sits between the outer and the lining for stability and structure. You can also add a layer of fusible fleece if you want some padding for protecting the device.

Maybe make it quilted with another layer and wadding?
Agree on plastic flexible chopping boards
You can also buy closed cell foam sheets which is more like what is inside laptop bags.

I use that polythene wrapping that comes in packaging of electrical goods.

I’d buy a laptop sleeve and include a pocket big enough to hold it. That way it can go between bags.

The laptop is going to make your bag heavy, so think about reinforcing the straps (rings, grommets and clips, buckles?) not just a stitched square which could rip.

Thank you for all your suggestions. I'll have a look online at interfacing etc, our local shop closed down and I don't know when I'll be in the city.

Good point about the cardboard in rain, don't know how I hadn't thought of that!

I've made a few bags and this flexible plastic is good especially for the base. You can buy it in different sizes and cut it easily to the shape you want. Also it is waterproof.
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