Frankie4 Unveils ‘Summer-proof’ Shoe Sub-brand

Australian brand Frankie4 wants to put comfort and practicality at the forefront this summer. Enter the new sub-brand Coast by Frankie4, which offers a lineup of “summer-proof” sandals.

The subline will also be available to shop in the United States via Amazon starting March 16 — a milestone for the brand as it aims to increase accessibility to American customers before peak summer travel.

Coast by Frankie4 is a response to the widespread issue of warm-weather shoes offering minimal support and durability. (While flip-flops might have become trendier than ever last year, their typical lack of support can be dangerous.)

At the heart of the fresh collection is the podiatrist-designed Sole Hero Footbed technology which provides built-in support for the heel, arch and forefoot. The leather shoe styles also receive a waterproof treatment to hold up against exposure to sun, salt and sand. The Coast line also boasts slip-resistant soles and a lightweight, flexible construction aimed at travel and warm weather environments.

Silhouettes include the T-strap Bondi sandal, the Isla slide with criss-crossing big toe straps, the Bronte style with slender straps, and the Venice slide with two thick woven straps.

“Women have not had many options between unsupportive slides and sandals that cannot withstand real warm-weather living and summer conditions,” said Gabrielle Thompson, director of footwear, in a statement. “Coast Collection by Frankie4 was developed to address that gap. Our aim was to bring genuine foot support to a category that has traditionally prioritized convenience over comfort.”

Coast by Frankie4 was developed over the course of five years, involving considerable material testing and refinement. The design team looked into contour profiles, toe shapes and construction methods ahead of defining the finalized concept, which brings together waterproof-treated leather uppers, a PU footbed akin to those utilized in the brand’s sneakers, and a durable rubber outsole. Resort wear inspired the styling, leading to a pool-to-bar aesthetic.

Founder and podiatrist Caroline McCulloch helmed the development of the footbed’s contouring, looking to Frankie4’s existing Sole Hero Footbed technology, which was shown to improve comfort by up to 64% for women with heel pain in a 2025 independent study by QUT in Australia.

Prototype testing went on for 18 months, encompassing several wear trials and laboratory simulations — including immersing the shoes in recreated seawater to see how it impacted durability and performance.

In addition to the Amazon launch, Coast by Frankie4 will be available across the brand’s own channels.