Lightweight Minimalist Bug Net for Bivvy Bag

Bivvy bags are a great shelter for ultralight backpackers or adventurers, and there is no better way to enjoy sleeping under the stars. The downside is that in some places there are creepy crawlers (sizes and dangerousness vary) that may come in to say hello. For many people this is not a problem at all (as long as there aren't dangerous insects in the area), but some others do mind waking up with little creatures running on their body (or just with the mere idea of it). And it is undeniable that mosquitoes and midges can be a real nuisance or carry dangerous diseases.

There is a big market of bug/mosquito nets to solve this problem. Most frequently these nets are designed to surround your bivvy bag completely, usually with some kind of frame that holds the net. To some extent, it feels that they somehow lessen the adventurous essence of the bivvy bag, resembling a stripped-down version of a tent. Although a bit pricey, some great lightweight and functional products can be purchased, but we found ourselves thinking why you wouldn't just carry your tent and save some money.

The bug net we had in our heads needed to keep insects outside the bivvy bag while being as small and fuzzless as possible. It also needed to maintain the adventurers inside us happy, so something minimalist with no frames or added comfort. Keeping all this in mind, we brainstormed some ideas and came out with the following bivvy mosquito net.

Sleep tight!

Step 1: Design

The design of the bug net is very simple: a cylinder of mesh that covers the bivvy bag from head to waist, with a cord at the bottom which allows squeezing the end of the cylinder tight around your body.

No supporting frame or fancy structure, but it does the job perfectly! You just get inside your bivvy bag, putting your head inside its hood, and sit upright. Get yourself and the bivvy bag inside the open end of the bug net and push it down towards your waist, when it's in place, tighten the cord so that no gaps are left between you and the net.

We've used it for several nights in very different conditions and it works great. The only issue is that the net may collapse and slightly touch your face, if that's a problem, you can wear a cap or a hat which will keep it away. If the net is a bit rigid it can be shaped so that it stays away from your face.

Step 2: Materials

What you need:

Mosquito net: a lightweight, see-through and soft mesh, not a rigid window one. Measures depend on your size, we used 1.80x0.70m for each, resulting in very roomy bug-nets.
Cord: any kind of string or cord would do, but ideally you'd want something resistant, maybe nylon. Dimensions again depend on your size, something around the length of the mesh you're using should do, we used around 1m to keep the net tight.
Cord-lock: any will do, just to tighten the cord.
Some fabric to wrap around the cord so that it can tighten the net (have a look at the picture). Length should be the same as the mesh, and just thick enough to wrap the cord and be sewn to the net.

Maybe the easiest way to obtain all the materials is to buy a commercial mosquito net and cut everything as you need. We found something like Gelert Single Mosquito Net perfect for our purposes. It has all the mesh, extra fabric, cords and cord-locks.

Sewing machine: not essential, but it makes the process much quicker and easier, and it allows using very fine stitches so making the product more durable. If you don't own/have access to one, have a look at your local hack/makerspace or ask around!

Step 3: Sew Everything Together

First, you want to create the mesh bag. Sew together the sheet of mesh to create a cylinder.
Then sew the extra fabric to the open end of the mesh cylinder.
This extra fabric needs to be folded and sewn onto itself so that there is a tube for the cord to go through.
Put the cord through the loop and fasten the ends with the cord-lock.

These steps should be easy for someone with sewing experience and require very little time. For a rugged version of the product, you can use double stitches and make sure that the ends of both the mesh and the fabric are clean cut so that it doesn't fall apart. You can use a second seam to achieve this, or slightly burn the ends with a lighter.