Comparison of Doublers and Inserts. They are very similar but Inserts are wider and longer and 6 layers each. Doublers are narrower and 2 layers thicker at 8 layers each. Either version will work. Narrower is often preferred in a fitted diaper or a true all-in-one diaper because of the nice way that the narrower shape fits in those diapers. Inserts are better in pocket diapers because the width is needed in the pocket or the pee might "miss" hitting the absorbency. A doubler isn't wide enough for a pocket diaper but may be used in a pocket in addition to something else (such as the Insert) that is wider. All of these are the same fabric and the same brand, Cloth-eez.
"Doublers" don't really "double" the absorbency. It's just the name that the piece of the extra absorbency that you add to a diaper is called. Another word for "doubler" is "booster". "Booster" and "doubler" mean the same thing - a fabric added to increase absorbency.
Absorbency order, least to greatest:
then Medium Insert and Large Doubler are equal in absorbency
Large Insert has the most absorbency by only by a little bit. Medium and Large Inserts are pretty close in size to each other.
For practical purposes, you can can consider Medium Insert, Large Doubler and Large Insert as all the same and just choose the size and shape that suits your needs.
New version doublers are the same sizes and now have rounded corners instead of squared off corners
Doublers add extra absorbency in any diaper.
Doublers are also useful for longer (night) naps. Doublers are useful the whole diapering time, so you might as well have some on hand right from the start.
Small doubler on a medium prefold
large doubler on a medium prefold
You can put either large or small doublers in the small or medium diapers. Newborn prefolds are enough absorbency on their own for most newborns, so most will not use any doubler with the Newborn prefolds but it could be done.
The same lovely prefold fabric as our beloved Cloth-eez® prefolds in a doubler. All sizes are 8 layers (8-ply) of 100% cotton. I love the prefold fabric because it's so soft and pliable. It is quilty just like prefolds are so they come out of the dryer curly and need to be flattened out by hand a bit. This is the nature of the twill prefold fabric. I like to match fabrics. When I use a prefold or a Workhorse diaper and choose to add a doubler, I like to use the same fabric, even though that doesn't really matter of course. Organic is unbleached organic cotton. Can you use these in pocket diapers? You can use 2 together instead of those smelly microfiber inserts, but we prefer our 100% cotton Cloth-eez Inserts for use in pocket diapers because they are wider for better coverage. This prefold fabric washes very easily and doesn't hold stink because it is 100% cotton. And best of all, they are very inexpensive. Doublers add additional absorbency in any style diaper. You can fit the size Small into the Newborn Workhorse diaper but it's a lot of cotton for a new baby. Small doubler fits nicely in a size medium Workhorse and large doubler fits nicely in size Large or XLarge Workhorse. If you already own size small doublers, just keep using them in your larger sizes. They are difference in size is probably not enough to justify buying more unless you actually need more.
Small 3.5"x 9.5" after shrinkage (yellow edges)
Large 4"x 12" after shrinkage (no color at edges)