Home » Make your own Cloth Pads » Hidden Core Pads

Hidden Core Pads

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 to something, 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 people 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 can mean the edges of the core can curl and usually means there is only the top layer and the backing layer through the rest of the pad, some people find they need some absorbency through the wing.

Another method for attaching the core is to do so on a “hidden layer” – this just means that you sew the smaller core piece onto another layer of fabric that is hidden inside the pad and not seen. This gives a smooth topped pad with no stitching lines (some people 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, it also gives another layer through the wings, which is good for the snaps (if your fabric through the wings is too flimsy the snaps can pull through or stretch the fabric there).  It also allows you to “zigzag” the core on so that the edges cannot curl.  This method is what I am going to show you here.

You can have channel lines with a hidden core – the channel tutorial goes into that.

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. You can do a hidden core in a serged/overlocked pad, but this tutorial doesn’t cover that.

For this method of pad making you will need:

  • Top fabric (the side that will touch your skin) (patterned cotton, velour, flannel/flannelette etc.)
  • Fabric for the hidden layer (plain white flannel/flannelette is best)
  • Core fabric (whatever appropriate, I use 2 layers bamboo fleece for a “medium/regular” pad)
  • PUL (if using it *)
  • Backing material (can be the PUL, or fleece, corduroy, cotton etc.)
  • Plus your snaps and thread of course

* Some PUL has a fabric side that is fine to have as the backing of a pad. If using one of these forms of PUL then use it in place of the backing material when it is mentioned in this guide.  Just remember to make sure you put it up the correct way – the “good” side of the PUL (the side you want exposed) should be against the “good” side of the topper when you sew it up.


Sewing the Hidden core layer

Easy peasy – sew your smaller hemp/bamboo etc. core layer onto your flannel layer.  Some tips here though…

  • Sew with a large “zig zag” stitch if your machine has one.  This will stop the edges curling or fraying, it also flattens the edge a little and makes the pad a bit smoother
  • As you sew, lift the presser foot briefly as you go every few cm – I find this helps stop the presser foot stretching your pad core fabric, so the end result is less likely to distort.
  • If you have multiple layers of core, make each layer slightly smaller than the other, so they are stepped – sew the smallest layer on first, then the next and the next – that way you should only be sewing through 1 layer of bamboo at a time, even if you have 3 layers of bamboo in total — a bit easier for your machine and it will feel less bulky as well.


Sewing up the pad

Now, there are 2 ways to sew up the pad, depending on what your preference is and your pad pattern instructions say.

  1. Cut-on-line  – The common method is to trace around your pad pattern/template, cut it out on that traced line, and then sew it up inside that cut edge, leaving a seam allowance.
  2. Sew-on-line – There is another method where you trace around the pad pattern/template but then you use that line to sew on, so you roughly cut the pad out and then trim it down once you’ve sewn it up.

The problem with cut-on-line is that when you are sewing it up, you’ll likely be trying to line up the right side of the presser foot with the edge of the fabric to use as the guide for where to sew.  Which sounds perfectly fine in theory, but when you are sewing around curves, and with some darker fabrics and in not great lighting sometimes it gets difficult to judge where that edge is.  So it’s easy to be a bit wonky when sewing it up.  Which can then make a slightly wonky looking pad.  Sew-on-line however means that you can more easily see where you need to sew, your presser foot probably has a little mark on it that shows where the centre point is where the needle will come down – and you have a line to guide you.

Sew-on-line does waste more fabric, but it is easier to get a nice evenly sewn pad, especially in more complicated styles.  It’s also good to use on slippery or stretchy fabrics like bamboo velour So I think in some ways it’s probably best for beginner sewers to use that method.  I’ll cover both methods here.  This sew-on-line is the method I have switched to using myself as I found my pads look better when I do it this way.  So I’ll do that method first.

– Note:  If you want to sew up a pad using the sew-on-line method, but your pattern template is designed to include the seam allowance, you could modify it to become a sew-on-line pattern by cutting your template down by however much seam allowance was included.  The Luna Wolf pattern is good for this as it actually includes the inner sewing line on the pad pattern template as well.  So you can simply cut the pattern out on the inner line instead of the outer line if you wanted to sew that one up as a sew-on-line method.

Pad construction method #2  – Sew on the traced line.

Firstly…. Despite taking care with the core placement and sewing it without tugging on the fabric, I sometimes find the hidden core layer will deform/warp slightly after I’ve sewn the core on when I’m sewing 2 or 3 layers of core on.  So what I always do after sewing the core on is to place my hidden core layer ontop of (the wrong side of) my top layer fabric, I smooth the hidden core layer out so it’s nice and flat, then I place my pad template down onto it again and check that it is still the right shape.  If it isn’t, then I try and smooth the fabric out to make sure it’s sitting right.  If for some reason it has warped slightly then I retrace the pattern to make sure that it is still the exact shape I need.

My pad template has marks for the centre points on each end and I transfer that mark onto my hidden core layer – as this helps to align fabric prints easily when the fabric has a definite pattern I want centered perfectly on the pad.

So, hidden core layer placed onto the pad topper.  I then pin it on and cut out that pad topper fabric – keeping those 2 layers together.  Then I take that combined layer and place that onto my pad backing fabric, readjust the pins to pin all 3 layers together and cut that out.

Alternatively you can simply layer all 3 fabrics together in the right order (core/topper/backer) and cut them all out at the same time – but you may waste a little more fabric doing it that way (but it is a lot quicker).

However you do it, you should now have your pad layers all roughly cut out with your hidden core layer at the very top. You will trim off all the excess later, so it only needs to be roughly cut out.  The other advantage of this method is that you can put pins anywhere you like in that outer part (not in the pad shape).  As that will either be cut off later or be in the seam allowance – so pin holes won’t be in your finished pad.

Which side up the hidden core layer goes doesn’t matter, but the top of the pad will look a bit smoother if the flannel side goes against the pad topper like I have here.   The layers you have should be

  • Hidden core layer (bamboo core on flannel layer)
  • Topper fabric (Good side down)
  • Backing fabric (good side up)
  • PUL layer (if having PUL)

The PUL can go either side up if it’s going to be hidden inside and you have a separate backing piece.  Some people will tell you it only works if you have the shiny side facing the core, but that isn’t true, it works either side up.  But it’s a bit easier to sew with if you have the fabric side against your sewing machine as it slides through better (so shiny side up in the fabric stack) – which is the “wrong” way according to some people, but I’m telling you it’s fine! :)

Sew around the pad on your traced line, remembering to leave an opening.  I find that to make the opening nice and secure so it doesn’t pull at the stitching when I’m trying to turn the pad out, I start sewing perpendicular (at right angles) to the opening (see the photo on the right).  Then sew around the pad.

When you come to the trickier curves, like the ends of the wings and the inward curve where the wing meets the body of the pad – go slow and as you go, stop while the needle is down, lift the presser foot, readjust your fabric, put the presser foot back down and sew a bit more.  This helps you get the curves nice and smooth without pulling on the fabric.


Once sewn up, trim off the excess, leaving as much seam allowance as you like.  I personally like to leave only a small seam allowance (about 1/2 cm) but it’s up to you.

If your pad shape has tight inward curves where the wing joins the body of the pad, you might like to “snip into the corners” – where you do a little snip about halfway into the seam allowance in that curve.  I like to do 3 little snips on a rounded corner like this.  It helps that curve sit nicely once it has been turned out.  Don’t cut too far in or you can get fraying.

(Click the image to see a larger view)


Now you should do a “zigzag” stitch around the seam allowance to prevent the edges fraying.  Make sure your zigzag doesn’t go past your stitching line, or you’ll be sewing into the pad itself.  It’s ok for the zigzag to go off the edge of the seam allowance – you are using this to bind the edges.

You could use an overlocker/serger to sew around the pad, or to do this edging – but I find in these pad shapes it’s difficult for the overlocker to handle the tight curves.  I also find the overlocker has a wider stitch length than I like, so I prefer the look of machine sewing for this type of pad.  But you can sew it up with an overlocker if you prefer.

Now I’ll show you my 2 (not so) secret tools of the trade.  A wet sponge and a chopstick :)

As you’re turning the pad out the right way, it can be tricky to get the ends of the wings and the curved ends to come out nicely – so that is where these 2 things are handy.

Firstly I use the chopstick to poke into the opening of the pad and press out the curves to make sure it is turned properly.  I also find that if I wet my fingers – that helps grip the fabric better, and what I do is basically go around all the edges of the pad and rub the fabric between my thumb and finger to make sure the pad is turned out properly. I also make sure those inward curves are sitting nicely by stretching them a little.  That’s a bit hard to explain so I made a video :)

The larger the opening you leave, the easier it is to turn.  Flannel and other grippy topped pads are also a bit harder to turn.  Just persevere.  You should get there eventually :)   Don’t forget to poke the edges of the turning hole over so that the opening is hidden and there is enough of the seam allowance inside the pad so that it’s caught in the top stitching.


Once that is all done, then it is time to do your top stitching.  Again, go slowly and when you come to the tighter curves go slow, and lift the presser foot (when the needle is down) to reposition the fabric if needed as you go.  If you have lots of thicker layers in the pad then sewing through all these layers can be a little trickier. You may want to use a jeans weight needle that is designed to go through heavier fabrics.


Pad construction method #1  – Cut on the traced line.

— This is my older guide.  Most of the same principles apply to this method as above, so use the above guide as well. —

Start by taking your hidden layer piece, and positioning the core pieces on top 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 plain white 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 as much of a step where the core starts, and will stop the core from curling or fraying at the edges.

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)
Top layer (Right side down)
Backing layer (right side up)
PUL (if using it separate to the backing)


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

obsitttutorial2_layersEither way is fine, but make sure your backing and top fabrics are touching each other, with their right sides touching. 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, so that when you sew it and turn it, the right sides of the fabric will be facing out.

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





obsitttutorial3_pinPin 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 – especially one near the edge of the pad, but you can use the pins where you’re only 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’d be likely to bleed, and you’re unlikely to want to pin the pad there anyway….. so pin away my friends… pin away!


Sew a straight stitch line around the pad. I normally leave a seam allowance of about 1cm.  Use whatever seam allowance your pattern says to leave or else your pad won’t come out the right size when it is finished.  If designing your own pattern, leave yourself plenty of seam allowance when you sew, it is better to have too much than not enough (you can always trim off the excess afterwards).

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 use 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.  But it does leave only a small hole on some pads.

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)

obsitttutorial5_sewzigzagNow that you have your straight stitching, and it’s caught all the layers, you can trim down your seam allowance.  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.

I do have an overlocker/serger, and using that so sew around the edges would be quicker, but there are 2 reasons I do it by machine instead… Firstly, the overlocker binds the edges, so you can’t see if all the layers have enough seam allowance, so you stand the chance of turning it and then finding one layer didn’t catch or something. And also, because I find a smaller stitch on the sewing machine leaves a nicer, neater finish than the overlocker stitches give when the pad is turned. You could always do one stitching line with the machine, and then overlock around instead of zigzagging.

obsitttutorial6_turnNow the fun bit, turning! (and by “fun” I mean “PITA” :)) 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.  Sometimes it reminds me of someone trying to give birth, and there can be a huge sense of accomplishment when you’ve finally delivered the pad-baby :D

obsitttutorial_openingOnce 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.

Then 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 probably neater if your handsewing skills are as lacking as mine are…. 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 and gives it a bit more stability. This is what the pad will look like before the top stitching.

obsitttutorial7_openingdtailFold in the open edges of the fabric 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.

obsitttutorial9_topstitchingAs you sew, make sure the seam where the top and backing fabrics meet is exactly at the sides of the pad. Fleece in particular likes to curl up at the edges I find.  You can use your fingers to guide the fabrics to where they need to go.  I keep a moist sponge by the sewing machine as I find it’s easier for my fingers to grip and roll the fabric if I’ve touched them to the sponge first.  Make sure that your topstitching has closed the opening properly, add snaps and you’re all done!