Love these and have tried many brands. They're cotton, but they hold their shape longer than many other brands. They run a bit small so if your child is at the top of the size range I would order the next up.
๐ฆ ViCherub Boys' Black Large Underwear - Pack of 3 | Boys' Clothing Collection
42 Review
๐ฆ HLMBB Dinosaur Toddler Underwear Training | Boys' Clothing for Easy Potty Training
44 Review
๐ Brix Boys Long Sleeve Tees - Optimized Clothing for Boys
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Comfortable & Durable: Lucky & Me Noah ๐ฉฒ Boys Boxer Shorts 5 Pack - 100% Cotton Tagless Underwear
49 Review
Arctix Youth Pants Reinforced: Large Boys' Clothing for Active Adventures
46 Review
๐ Bold Pack Sleeve Active Hoodie Sweatshirt Set for Boys' Clothing - Stylish and Comfortable!
47 Review
๐ Fruit of the Loom 6 Pair Cushion Ankle Boys' Clothing: Comfy and Stylish Selection for Active Boys
57 Review
๐ Boys' Outdoor Climbing Convertible Trousers - Waterproof | Clothing
47 Review