In-depth baby product reviews led by a Pediatrician

Woolino 4 Season Ultimate Review

High quality sleep sack that uses wool to help regulate temperature, but is quite expensive and high maintenance
Woolino 4 Season Ultimate
Credit: Woolino
Editors' Choice Award
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Price:   $100 List | $99.99 at Amazon
Pros:  Large age range, durable, easy size adjustments
Cons:  Expensive, requires special cleaning care
Manufacturer:   Woolino
By Abriah Wofford ⋅ Senior Review Editor  ⋅  Nov 18, 2021
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86
OVERALL
SCORE


RANKED
#1 of 12
  • Baby Comfort - 40% 8
  • Ease of Use - 40% 9
  • Durability - 20% 9

The Skinny

The Woolino 4 Season Ultimate is a sleep sack made from merino wool and organic cotton. The temperature regulating properties of the material make it a perfect choice for parents who want to use the same sleep sack year-round. While the price tag is more than triple that of the competition, the great adjustability and high-quality construction of the sleep sack make it a long-term investment that you may find to be worth it over time. We love the functionality of the Woolino, and it is one of our top choices for nighttime wear for our babies.

Compare to Similar Products

 
Awards Editors' Choice Award Editors' Choice Award Best Value Award Best Value Award Top Pick Award 
Price $100 List
$99.99 at Amazon
$30 List
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$25 List
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$35 List
$13.58 each at Amazon
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Pros Large age range, durable, easy size adjustmentsEasy to use, Velcro free, quality materialSoft fabric, organic cotton, easy to useSecure wrap, soft material, hip friendlyHighest quality, breathable and soft material, versatile, large
Cons Expensive, requires special cleaning careLots of wrapping, layers might get warmVery lightweight, runs largeLoud Velcro closure, more steps to swaddleHarder to use than sleep sacks, difficult to get tight enough
Bottom Line High quality sleep sack that uses wool to help regulate temperature, but is quite expensive and high maintenanceAn escape-proof swaddle that is a bit more time-consuming with lots of wrapping, but is free of snaps, zippers, and VelcroLightweight organic cotton sleep sack that has a large age range, but may need to be sized down and may not be good for colder climatesBudget-friendly swaddle with a hip-healthy design, but not as simple to use and the Velcro is loudSoft swaddling and multi-purpose blanket uses excellent materials, but is harder to use than sleep sacks
Rating Categories Woolino 4 Season Ul... Miracle Blanket Burt's Bees Baby Be... Ergobaby Swaddler Aden + Anais Classi...
Baby Comfort (40%)
8.0
8.0
7.0
7.0
9.0
Ease Of Use (40%)
9.0
7.0
8.0
7.0
2.0
Durability (20%)
9.0
8.0
7.0
8.0
9.0
Specs Woolino 4 Season Ul... Miracle Blanket Burt's Bees Baby Be... Ergobaby Swaddler Aden + Anais Classi...
Style Sleep Sack Swaddle Wrap Sleep Sack Velcro Swaddle Traditional Swaddle Blanket
Material Organic Cotton with Merino Wool Core Cotton GOTS Certified Organic Cotton Cotton Cotton Muslin
Zipper Direction Two-way NA Reverse NA NA
TOG rating NA Not Listed 0.5 0.5 NA
Age Range 2 Months-4 Years 0-14 Weeks 0-18 Months 0-3 Months All ages
Available Sizes Baby, Toddler One Size Small, Medium, Large One Size 47" x 47"
Washing Instructions Machine wash cool. Can be tumble dried on No Heat or Air Dry setting. Hang to dry whenever possible. Machine wash cold, tumble dry low Machine wash cold and tumble dry on low Machine wash, tumble dry low Wash with like colors, do not wash with any thing that could snag (velcro, buttons, snaps)

Our Analysis and Test Results

The Woolino company was founded by a new mom, Mimi, who wanted to keep her first child safe and cozy through the night. After scouring the sleep sack market and coming away unsatisfied with the options, she decided to make her own. With ambitions to create a sleep sack that was both safe and comfortable for babies and toddlers, she needed a high-quality and multi-seasonal material. Mimi found cotton too lightweight for winter and synthetic suits too prone to overheating in the summer; merino wool was a perfect choice. Since its inception in 2010, the company took off, and Woolino is now one of the top manufacturers of wool-made baby sleep sacks and clothing.

Performance Comparison


The Woolino 4 Season Baby fits babies from 2 months up to 2 years.
The Woolino 4 Season Baby fits babies from 2 months up to 2 years.
Credit: Abriah Wofford

Likes


The Woolino 4 Season Ultimate sleepsack is one of our favorite options for dressing your baby for bedtime. With two available sizes, you can use this sleep sack from 2mo-2y and 2-4y. This combined total of nearly four years is the longest usage span of all the products we tested, and with proper care, the durable materials last well past the point when your baby outgrows the sack. It is an item that can be passed down to a little brother, sister, or cousin when the time comes.

The side zip makes dressing the baby much easier.
The side zip makes dressing the baby much easier.
Credit: Abriah Wofford

The Ultimate sleep sack has a core layer of fine merino wool encased in soft organic cotton that is cozy against your baby's skin. Wool is a naturally breathable and temperature-regulating material that helps to lessen the potential of baby overheating or getting too cold while also eliminating the need to purchase multiple products for different seasons. Woolino merino wool is Woolmark and Oeko-Tex 100, and their cotton is GOTS and Oeko-Tex 100 certified organic. We appreciate that the company uses high-quality and environmentally responsible materials and love that they strive to reduce the number of chemicals in their products.

The armpit and shoulder snaps on the Woolino make it adjustable for...
Getting our little tester dressed in the Woolino was much easier...

You can adjust the fit of the sleep sack through a series of discreet buttons near the armpits and shoulders. These snaps keep the material snug against the baby's body, and as your little one grows, they can be left open to accommodate. Thanks to a zipper that runs around the entire edge of the garment and snappable shoulder straps, the sleep sack can be opened and laid flat before placing your baby on top. We appreciated this feature the most when we had to dress an already sleeping baby and didn't have to squeeze their arms to fit through small armholes or try to pull the fabric out from underneath without waking them.

The Woolino is made for babies as young as 2 months who are...
The Woolino is made for babies as young as 2 months who are transitioning out of the swaddle stage.
Credit: Abriah Wofford

Dislikes


There are very few things that we would change about this sleep sack; it'sjust that great. However, there are a few things to note before buying. Wool is a wonderful natural material, but it requires some extra care if you want to avoid shrinkage and help your sleep sack last through the years. You must wash the Ultimate sleep sack on a gentle/cold cycle, and while you have the option to machine dry on a no heat cycle, Woolino recommends line drying whenever possible. The washing process may take longer than some other products, and you may want to purchase a backup for washdays as the triple-layered fabric may take a while to dry.

Woolino claims their sleep sack is appropriate for babies as young as two months, shortly after your baby transitions out of the swaddling stage. However, parents complain that there is WAY too much fabric for smaller infants, and it tends to get twisted and tangled.

Lots of extra fabric on the Woolino leaves lots of room to grow, but...
Lots of extra fabric on the Woolino leaves lots of room to grow, but can be a hassle to deal with when your baby is small.
Credit: Abriah Wofford

We purchased the smaller size for our two 1/2-month-old tester and found this to be only somewhat true. There was a lot of excess fabric around her legs. However, the shoulder and armpit snaps keep the fit close and prevent the fabric from riding up towards her face. The extra material is likely more of an inconvenience for parents to deal with, but it does not affect baby comfort or safety.

Our 2 1/2mo tester was comfy and cozy in the Woolino sleep sack.
Our 2 1/2mo tester was comfy and cozy in the Woolino sleep sack.
Credit: Abriah Wofford

Conclusion


Like us, you probably want your baby to have a comfortable, cozy, and safe sleep environment. The Woolino helps deliver on all fronts by keeping loose blankets out of the crib and using high-quality environmentally responsible materials that keep your baby snug as a bug in a rug. While it is a much more substantial investment than any other product we tested, with proper care, this garment can last for years and go from child to child. If your budget allows, we highly recommend the Woolino 4 Season Ultimate sleep sack.

Manufacturer Video



Abriah Wofford

Honest, objective reviews. Led by a Pediatrician.

BabyGearLab was founded by a Pediatrician Mom with a mission to provide a reliable, independent, source of information to new parents. Our experts have tested thousands of baby and kids products to share key performance, health, and safety findings. We spend tens of thousands of dollars crash testing car seats to inform our ratings. And, we combine our review work with gobs of expert parenting advice. To assure complete independence, we buy all the products we test ourselves. No sponsored content. No ads. Just real, honest, side-by-side testing by people who care.

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