BIAB Refill vs. New Overlay: What's the Actual Difference?
This is one of the most common points of confusion guests run into when booking their next nail appointment: is it time for a refill, or do you actually need a new overlay? The two aren't interchangeable, and booking the wrong one can mean an appointment that runs longer than expected, or doesn't fully address what your nails need.
What a Refill Actually Does
A refill fills in the gap left by new nail growth, blending fresh product into the existing BIAB base that's still structurally sound. It's a maintenance appointment, not a rebuild; the original overlay is still doing its job, it just needs the gap addressed.
What a New Overlay Actually Does
A new overlay means removing what's there and starting over with a fresh application. This is the right call once too much time has passed for a simple gap-fill to make sense structurally, or if the existing product has started lifting, cracking, or you've had more than 6 infill appointments.
Why the Timing Line Matters
Most guests are in refill territory around 2 to 3 weeks out from their last appointment. Past about 4 weeks, the growth gap and the condition of the existing product usually mean a refill isn't enough. That's when a new overlay makes more sense.
Why Booking the Wrong One Causes Problems
If you book a refill appointment but you're actually well past that window, your nail technician may need to convert the appointment on the spot, which can affect timing and pricing you weren't expecting. Booking accurately based on how long it's actually been saves everyone the surprise.
A Simple Way to Track It
2 to 3 weeks since your last BIAB appointment: book a refill
4 or more weeks since your last BIAB appointment: book an overlay instead
Frequently Asked Questions
What happens if I book a refill but it's actually been over a month? Your nail technician will likely need to treat it as an overlay instead, since a simple fill isn't structurally enough at that point. That can change the appointment length and price.
Can I always tell myself which one I need? The general timeline is a good guide, but if you're ever unsure, it's easier to just mention how long it's been when booking so we can get you into the right appointment type.
Does a new overlay mean starting from scratch on my nail health? Not necessarily; it means removing and reapplying the product, but the underlying natural nail growth and health you've built up in the meantime is still there.
Not sure which one you're due for? Just let us know how long it's been since your last visit when you book, and we'll get you into the right appointment.
We'll see you soon, the Hazel Team.
