Wool Interlock / Recycled Wool / Upcycled Wool ? Felted?

I recently had a question about wool interlock: “Is your wool interlock new and how is it different from recycled/upcycled wool?”


Wool interlock is fabric made from fine wool yarn, spun from sheep wool. It is milled like any other fabric, with huge knitting machines, and the stitches are tiny. The fabric looks the same on the front and back, with little “V”s. By definition, interlock fabric is “a fabric knitted with closely interlocking stitches that allow it to stretch”.

Wool Diaper Cover


Yes, the wool interlock fabric I buy is made from new wool.


Recycled wool can have many meanings. For my purposes, recycled/upcycled wool is wool from sweaters that I wash, cut and sew into something new. These sweaters come from a warehouse in NYC where I go once every 6 months to hand pick sweaters for weight, color, quality, thickness, fiber content, softness, etc. The wool can be merino, lambswool, angora, camel, yak, or cashmere, with at least 80% wool content.


woolie wrap: an outer layer of recycled wool, an inner layer of interlock wool (unwashed/unfelted (shrunken))

-it is milled as a fabric, not milled into heavier weight yarn that is then machine knit into a sweater
-it is less “holey”- just as you have to look closely at a tshirt to see the knit design, this fabric is more substantial than wool sweaters
-it is softer: it is merino wool, which is arguably the softest but most durable wool fiber. It has not been chemically treated like many wool sweaters have been. It is undyed (unless I dye it) so it has less chemical treatments. Many sweaters manufactured for companies are treated with chemicals to be machine washable and or moth resistant.
-it is stretchier: it is milled with a 97% merino wool, 3% spandex. The spandex make it stretchier and it also “remembers” its shape. A 100% merino wool sweater is more prone to stretch out and then forget its original shape and be baggy. Spandex makes the wool more durable as well.

My listings in my shop explain what wool is used and where on each product.

Woolie wraps are an outer layer of recycled wool and an inner layer of interlock wool that has NOT been washed/felted/shrunken. (see photo above)

“hybrid” soakers are a body of recycled wool and waist/leg cuffs of wool interlock that has been felted.


hybrid soaker: recycled body, interlock waist/legs

interlock soakers are all interlock that has been felted. Some are hand dyed wool. (see photo above)

longies have a wool interlock (felted) waist and a recycled body/legs


longies: interlock waist and recycled body/legs

harem longies have recycled legs/bum circle with wool JERSEY waist/leg cuffs: jersey is a lighter weight knit than interlock. There is one pair of all interlock longies for sale now.

harem longies: wool jersey waist/leg cuff, recycled body/bum circle

harem longies: wool jersey waist/leg cuff, recycled body/bum circle

weensy woolies (newborn wool wraps) are 2 layers of unwashed/unfelted/unshrunken wool interlock.

2 layers of unwashed/unfelted/unshrunken wool interlock

2 layers of unwashed/unfelted/unshrunken wool interlock

What is felted wool? What is the benefit of felted vs unfelted wool?

Felted wool is wool that has been washed and agitated in hot and cold water, rubbing the fibers against themselves and ultimately resulting in shrinking of the wool and tightening of the fibers. I wash my sweaters on medium to hot temperature and a regular wash. This causes a “medium” felting of most sweaters: they could felt more if I were to wash them on hot again, but they serve a great purpose of wool diaper covering while still being stretchy. When you felt wool sweaters completely or heavily, the stretchiness goes away. This reduces the comfort level of garments made after it. However, a denser wool will be more bulletproof against leaks. Very felted wool will also be thicker and less trim than unfelted or partially felted.

Wool interlock and jersey fabric can be felted before being cut and sewn. I felt my wool interlock and jersey before making interlock soakers. I do NOT felt it or wash it at all before making the newborn wraps and one size wraps. These layers of wool will shrink a little with the first wash/lanolization. After that, with careful washing and drying and care, they should not shrink further. The benefit to this is that it is more trim. Again, the wool interlock and jersey with their spandex added remain stretchy and soft even after being felted!


2 responses to “Wool Interlock / Recycled Wool / Upcycled Wool ? Felted?

  1. Hi!
    Would you say there is a difference as far as efficiency/wicking is concerned between “purpose-made” wool diaper covers (made out of wool interlock for example) and upcycled wool diaper covers?

    • Hi Val-
      I would say that merino wool interlock performs better for both efficiency and wicking. It is generally more durable, tighter knit, and more suited to diapering than wool sweaters. Thanks!

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