Around 12–18 months, most babies are walking, and separates start making more practical sense than one-piece rompers for both movement and easier nappy changes. Popees' 12–18 month sets pair a soft t-shirt with an elastic-waist bottom.
Why separates work better now
Once a baby is walking, a two-piece set allows more freedom through the hips than a one-piece romper, and makes nappy changes and eventual potty training easier to manage.
Bottom fit for new walkers
A slightly looser cut through the seat and thigh accommodates the wide-legged stance new walkers often have, without the bottoms feeling restrictive.
T-shirt length
A t-shirt that sits at or just below the waist (not too long) avoids getting stepped on or caught underfoot as a new walker moves around.
Why switch from rompers to separates at this age?
Separates generally offer more freedom of movement for a new walker and are easier to manage for nappy changes and eventual potty training.
What bottom fit works best for a new walker?
A slightly looser cut through the seat and thighs accommodates the wide stance many babies have when they first start walking.
Should t-shirts be tucked in or loose for toddlers this age?
Loose is generally more practical and comfortable; a t-shirt cut to the right length shouldn't need tucking to stay out of the way.
How often will I need to size up at this stage?
Roughly every 3–4 months is typical, though this varies by individual growth rate.
We cut this age's bottoms with a wider seat specifically for the stance new walkers naturally take.
