Yay for making your own, best way to get the result you want, and best way to customise what type of absorbency you need.
This is a good table to go by.
| Insert Type | Absorption Amount | Absorption Speed |
| Microfiber | 💧💧 | 💧💧💧💧💧 |
| Microfiber/Bamboo blend | 💧💧💧 | 💧💧💧 |
| Cotton | 💧💧💧💧 | 💧💧💧💧 |
| Bamboo | 💧💧💧💧 | 💧💧 |
| Hemp | 💧💧💧💧💧 | 💧 |
| Zorb | 💧💧💧💧💧 | 💧💧💧💧 |
However it doesn't account for compression leakage. Most to least lossage would be:
Microfiber.
Microfiber/Cotton/Bamboo Blend.
Bamboo.
Cotton. (not a lot in it between cotton and bamboo though I feel cotton just slightly outdoes it).
Zorb.
Hemp.
A few tips I'll share from my own experience making inserts/diapers.
1) Never use more than 4 layers on one insert, 3 is ok, 4 is on the edge. More than that and you run the risk of it not fully washing, rinsing out detergent or drying. Allowing bacteria / mold to grow.
2) Depending on what diaper/cover you are using rectangles are a good bet for shape, an hour glass with wider back end can be good if the diaper/cover is designed for it and can also help to spread out the ridge that can show through thinner clothing to make it less noticable.
3) You can actually use half as many layers as you want if you make the insert twice as wide, e.g. want a 4 layer insert 18cm wide, cut 2 pieces 36cm wide (with seam allowance) and sew them together around the edge. You can now fold this in half to make your insert and after washing you can open it out to dry much faster.
You could also make thicker inserts this way (remembering the 4 layer rule), cut 2 pieces 36cm and 2 pieces 16cm wide and about 2cm shorter. Lay out one of the larger pieces and sew the 2 smaller ones onto it equal distance from the edges with about 1.5cm gap between them, now place the other large piece on top and sew the 2 larger pieces together all round. when folded you have 6 layers but for washing and drying it's in the nice safe zone of 3 layers.
4) Zorb can supposedly replace 2-3 layers of bamboo/cotton Terry and is very thin but lots of layers of it can get quite stiff. Use the 3D Zorb over any of the others as it is already between another fabric and just needs the outer edges serged.
5a) Depending on your usage having the right type of absorbency is better than just having lots of absorbency. Enough layers of bamboo might be able to hold 1800ml but If you are weeing like 7-800 ml in one big go and if it can only absorb say 200ml in 10 seconds you are likely to have leaks still as it can't soak it fast enough.
A good mix of fabrics can prevent this if layered correctly, fastest soakers on top (close to skin) and most capacity/compression hold on the bottom. so from the table above:
Microfiber on top of cotton, or microfiber on top of Zorb on top of bamboo.
Zorb is an odd one in that it is fast and holds a lot but it tends to be best in the middle.
It is often good to have at least one or 2 layers of microfiber on top of the stack, it is terrible at holding with compression but will very quickly soak up wee as fast as it comes out and pass it down to the slower absorbing but better holding layers.
You don't need some of everything just pick a strong holding fabric (Hemp>Cotton>bamboo) and use either Zorb or microfiber as a fast acquisition layer (think like the ADL in disposables).
5b) Again depending on what you are inserting them into it can be good to make a couple of "Top Layer" inserts. These are thinner inserts that have a dry feel fabric on one side, not much point though if they are going into a pocket diaper that already has a built in stay dry layer inside.
There are several options to choose from including microfleece, suede cloth, serpa and my latest favourite athletic mesh. These inserts are meant to be used with other more absorbent inserts but with the stay dry fabric on top against your skin for comfort and cleanliness.
If using separate loose inserts these are best done with one or two layers of microfiber to get that fast absorb on top with a dry feel and with the rest of your inserts under them being bamboo/hemp/cotton/Zorb etc. Or you can make them as a tube as shown in the next tip where the stay dry fabric will be attached to your highest capacity/best compression holding fabric.
6) Make a tube / insert holder. These will be about 2-3cm wider than your other inserts and consist of a couple of layers of high capacity/holding fabric sewn together at the front and back with a single layer then placed on top and everything sewn down the sides together. This creates a tube into which you can place additional inserts (possibly different fabrics) to keep everything together and prevent them moving around and twisting.
It also helps with rapid changing as you can prepare one of these with however many layers of inserts you want and fold it up ready, when needing to change just lay it out in place and off you go rather than having to prep each insert as you change.
This is best done with the stay dry layer on top as mentioned above, 3 layers of Bamboo or cotton Terry and some athletic mesh on top, this way no matter what other inserts you put inside to bulk it up you will have a good holding fabric on the bottom and a stay dry layer next to your skin.
