Hidden Core Tutorial

Most cloth pads are made with an absorbent “core” (cotton/hemp/bamboo fleece or terry usually) sewn into the pad down the centre where absorbency is needed, so that you don’t have bulky thickness you don’t need at the edges of the pad and in the wing. This core needs to be sewn down, to prevent it from sliding around inside the pad.

You can simply sew the core to the top layer of the pad, which gives “channel lines” of stitching ontop of the pad. Some women find this helps to direct the flow, and some like the look of these. If your sewing is a little wonky though, it can really show in these stitching lines on top, and spoil the look of the pad. Also this method of attaching the core to the top layer, usually means there is only the top layer and the backing layer through the rest of the pad.

Another method for attaching the core is to do so on a hidden layer. This gives a smooth topped pad with no stitching lines (some women prefer this), and has the advantages of not only does it not matter how messy your sewing of the core is, but you also end up with an extra layer of absorbency through the entire pad, which can be helpful if your flow does not go just where the core is. This method is what I am going to show you here.

This type of pad is referred to as “turned and topstitched”, because it is sewn inside out, and then you “turn” it out the right way, and do a “topstitch” line of sewing around the edge to neaten it off.

For this method of pad making you will need:

  • 1 pad piece for the top (patterned cotton, velour, flannel etc.)
  • 1 pad piece for the hidden layer (flannel/flannelette is best)
  • Pad Core (whatever you find appropriate for you, I use 2 layers bamboo fleece for a “medium” pad)
  • 1 pad piece of PUL/waterproofing (if using it)*
  • 1 pad piece of backing material (can be PUL, fleece, corduroy, cotton etc.)
  • Plus your snaps and thread of course

* Some PULs have a fabric side that is fine to have as the backing of a pad. If using one of these forms of PUL you can choose to have a separate backing (fleece, printed cotton etc.) or not (having the PUL as the back). If you want to have fleece or printed cotton as a backing layer, you can have the PUL layer hidden behind that if you wish.

Start by taking your hidden layer piece, and positioning the core pieces ontop of this so they are central. Because nobody will ever see this, it doesn’t matter if it is slightly out, so you can just visually get it in the centre. I like to use flannel/flannelette as this hidden layer because it is thin but has some absorbency. Something like a plain cotton could be used too, but it will not offer much absorbency. Once you are happy with the position of the core, use the biggest “zig zag” stitch your machine will do, and sew around the edges of the core, sewing it to the hidden layer piece. You can straight stitch this if your machine doesn’t do “zigzag”, but the “zigzag” stitch helps to squash the edges flat so you don’t feel a step where the core starts.


If you are using something thick, like regular cotton terry (what they make towels from), the core will probably be quite thick. So you can run a couple if stitching lines up and down the pad to help squash that a bit flatter to keep the pad thin.

The next step is to assemble the pad. Lay down the pieces in the following order.

Hidden core layer (either side up, but I do core side down)
Top layer (Right side down)
Backing layer (right side up)
PUL (if using it separate to the backing)

So your backing and top fabrics are touching eachother, with their right sides touching, and the core layer is on the very top, and if you are having a hidden waterproof layer, then it is the bottom most layer. If using the PUL as the backing, make sure you sew it together with the laminated side down and the fabric side touching the top pad piece.


In this example we have a white microfleece back, the patterned cotton top and the cream flannel hidden layer with core.

Pin the pieces together. Some people get scared of using pins for cloth pads, worrying that there will be leaking through the pin holes. This is only an issue if you are using a waterproof layer like PUL, other fabrics are naturally holey anyway, so a pinhole makes no difference. Even with PUL, you can pin through it and it shouldn’t make a difference. Not only should a pad not be so full that it can leak through a pin hole, but if you use the pins properly, you’re only going to be pinning through what will be the seam allowance, and will get perforated by the sewing needle anyway. Pinning into PUL would really only cause problems if you pinned further into the pad, where you wouldn’t need to pin… so pin away!  Just keep the pins within what will be the seam allowance if you’re concerned about pin holes.


Yes, the astute of you may have noticed that my layers don’t quite match up. They rarely do. I suppose the way to avoid that would be to lay out your 3 fabrics and cut them all out together, but any slight variations won’t matter since they are in what will be the seam allowance.

Sew a straight stitch line around the pad. Leave yourself plenty of seam allowance (you can always trim off the excess afterwards), perhaps aim for about 1cm.

Don’t forget to leave an opening! You need this to turn the pad out the right way. How big a gap you leave is up to you. The bigger the gap, the easier it is to turn, but the more you have to sew closed. The smaller the gap, the neater it will look but it will be harder to turn. Pick a spot to leave the gap that will be easy for you to close later. I like to pick a spot on the wing, because it’s straight, less obvious and means I don’t have to use one of the curved ends and spoil the curve

Once you have sewn around it (leaving your gap), check all the edges to make sure you have all the layers showing in the seam allowance. If a layer isn’t showing in your seam allowance, it means it’s not been caught by the stitching and will leave a “hole” when you turn it. (you can leave it as it is, but it will fray when it’s been washed)

Now that you have your straight stitching, and it’s caught all the layers. I like to do a “zigzag” around the edges. This gives it an extra row of stitching just in case, and it stops the fabric fraying. If you’ve left a large seam allowance, trim it down to about 1/2cm (1/4″), then do your “zigzag” around the edges. Remembering not to do the part you left open for turning.


Now the fun bit, turning! This can be a bit tricky, if your core is thick and the opening you left is small, but persevere and you should get it turned out. Sometimes it helps to try and get the ends out first. Anyway, Once you have turned it out, make sure your wings and the front and back curves are fully turned, I like to use a chopstick or something similar to run around the inside edges to make sure it’s all turned out properly.


You need to sew closed that opening. You can hand sew it, but you can do it with the top stitching, which is quicker, easier and neater. What’s the “topstitching” – that’s the line of sewing that runs around the edge of a pad. It not only makes the pad look neater and more finished, but it stops it moving about at the edges. This is what the pad will look like before the top stitching.


Fold over the backing layers and the top & hidden layers so that you have folded over about the same amount as the seam allowance is. You should be left with an opening that looks something like this:


You can pin this closed if you like. Ironing the pad now can help to keep the edges sharp and give a better result while sewing, but you don’t have to iron it. Using the sewing machine, position the needle about 3mm (1/8″) from the edge of the pad, and sew around the edge of the pad. You need to make sure that you’ve folded in enough of the seam allowance in the opening so that your topstitching will seal the opening properly. You may be able to use the marks on your sewing machine’s foot as a guide to keep it a constant width. This will topstitch the pad and sew closed the opening at the same time.

obsitttutorial_closeopening obsitttutorial_topstitching

As you sew, make sure the seam where the top and backing fabrics meet is exactly at the sides of the pad. You can use your fingers to guide the fabrics to where they need to go. Make sure that your topstitching has closed the opening properly, and if so, add snaps and you’re all done!