Ella's Wool

Baby Base Layer Tank Onesie (Gray)

Our Super Soft Base Layer Tank Onesie Keeps your baby warm when temperatures drop below 50F/10C

  • Base layer Merino wool tank onesie for babies 0-18M
  • Made from butter-soft, non-itchy 100% pure merino wool
  • 21.5 microns (babies are less active so these thermals are warmer than usual)
  • Keeps babies warm even when damp
  • Standard 100 by OEKO-TEX


When the winter arrives, and it’s freezing outside, it can be tempting to keep your little one inside and safe from the cold. Norwegians, however, have been keeping their babies warm and cozy in harsh winters for hundreds of years. How? By clothing them with soft wool.

Our base layers are made from 100% ultra-soft merino wool. When humans discovered this ‘miracle fiber,' they began to use it to create clothing that keeps people warm, even in freezing cold climates.

Merino wool is perfect for babies because the fabric keeps their fragile bodies warm and toasty while still regulating the body temperature. The result? A happy baby that isn’t too hot or too cold, but just right. 


Our base layers are hands down the softest merino wool we’ve ever felt - it’s silky smooth like butter! Therefore, it’s the perfect material to rest against your baby’s delicate skin all day long. Unlike traditional wool, merino wool's super-fine fibers are non-itchy. If this will be your first time trying merino wool for your baby, we say go for it.

Merino wool stays warm when damp, so if your little one gets a little wet, she will still be comfortable. This "magical" fabric can absorb up to 30% of its weight in moisture before it feels wet. That means that if your baby spits up or is having a little leak at night, she won't get soaking wet and cold compared to for example cotton fabric. Wearing merino wool can be a game changer for many babies living in colder areas.

Be sure to wear the base layers next to the skin (the wool cooperates with the heat and moisture on the surface of the skin, and it's essential that there is no other fabric in between (except a diaper, of course).


Taking care of the base layers needn’t be any trouble as merino wool is naturally odor-resistant, anti-microbial, and grease-resistant. You don't have to wash them after every use if there are no spots, simply hang them up to air out. When it's time for a clean, put them in your washing machine on a wool/delicate program with a good wool detergent, and hang them up to air-dry afterward.


Side seam down to top of leg opening:

  • 3-6M: 6.75"
  • 6-9M: 7.5"
  • 9-12M: 8.5"
  • 12-18M: 9.5"