What is Wool Weight or Thickness
What does it mean?
WOOL WEIGHT or THICKNESS
The "weight" of the cover refers to the thickness of the wool used.
Thick/heavy covers are really great for very heavy wetters, overnight, long car rides, etc. any time compression leaks (leaks through the cover from a SOAKED diaper) are likely. They are generally too thick to go under fitted clothes but work great under pj's, skirts, and sweats. Because of their bulkiness, they are often not a good fit on tiny babies.
Midweight covers are great all-purpose covers. They are trim enough to go under a lot of different clothing but thick enough to work for overnight and naptime for most babies. These are what I generally recommend for first-timers to wool unless they know they have a VERY heavy wetter. Even if you're babybear generally leaks through covers, you can still use midweight and just bolster the absorption of your diaper by adding a soaker layer down the center. This weight also tends to provide the greatest variety in colors and patterns as it is most common.
Thin/lightweight covers are just that. These fit best on little babies and newborns because they are not bulky. In general they require frequent changes to prevent leaks although some trim wools actually provide very good protection. These include Merinos (which are ultrafine wools and so are densely knit yet lightweight) and Meltons (a dense, spongy, felted wool similar to what you find in outerwear like Pea Coats).
One other important note: all weights may be either stretchy or woven (non-stretchy) wools. Non-stretchy wools retain their shape well and hold up better if accidentally washed and/or dried, but they will not fit as large of a size range because they have very little 'give', while stretchy wools will fit larger babies and toddlers.