Apparel Prototyping: Kool Pressions Therapeutic Compression Leggings

A patent-pending stirrup legging taken from sketch to custom-printed, wearable prototypes.

GARMENT DESIGN
COMPRESSION ENGINEERING
PATTERN & PRINT DESIGN
MATERIAL SELECTION
PROOF-OF-CONCEPT PROTOTYPING
HIGH-FIDELITY PROTOTYPING

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Written by Ralph Hill, Mechanical & electrical systems, 3D manufacturing

Prototyping Engineer

Published August 30, 2026

Project snapshot

Rhonda Young came to LA NPDT with a concept for patterned therapeutic compression leggings with exposed toes and heels. We designed the garment, engineered the compression, and produced custom-printed high-fidelity prototypes she could use to validate the idea.

The LA New Product Development Team delivered Apparel Prototyping: Kool Pressions Therapeutic Compression Leggings, covering garment design, compression engineering, pattern & print design, material selection, proof-of-concept prototyping and high-fidelity prototyping. Our in-house team handles concept design, engineering, prototyping and manufacturing readiness under one roof in Ruston, Louisiana.

Services applied: GARMENT DESIGN, COMPRESSION ENGINEERING, PATTERN & PRINT DESIGN, MATERIAL SELECTION, PROOF-OF-CONCEPT PROTOTYPING and HIGH-FIDELITY PROTOTYPING

Rhonda Young approached LA NPDT with a clear idea and no way to hold it in her hands. Kool Pressions was to be a therapeutic compression legging that also flattered the lower body — cut as a stirrup so the toes and heels stay exposed, and finished in bold, unapologetically extravagant prints rather than the clinical black most compression wear defaults to. Our job was prototyping in a material we do not usually touch: fabric.

We designed the garment, engineered how the compression would actually be achieved, produced a proof-of-concept prototype, then printed custom patterns and built high-fidelity prototypes Rhonda could wear, photograph and put in front of prospective buyers to validate the concept.

The Brief: Compression That Someone Would Actually Want to Wear

Therapeutic compression garments work by applying graduated pressure to the limb — higher at the ankle, tapering upward — a mechanism used clinically for circulation and swelling management (NCBI StatPearls: compression therapy). They also, almost universally, look medical. Rhonda's premise was that the two are not linked: the same engineered pressure can sit inside a garment with a slimming cut and a print worth showing off, and it will get worn far more often as a result. The stirrup detail was functional as much as aesthetic — leaving the toes and heels exposed keeps the garment wearable with sandals and open shoes, and avoids the hot, bunched foot that stops people wearing full-foot compression through a day (MedlinePlus on wearing compression stockings).

Garment design. Silhouette, panel layout, seam placement and the stirrup cuff geometry that holds the legging down without cutting into the arch.
Compression engineering. Fabric selection, stretch and recovery targets by zone, and the pattern reductions that turn a stated pressure into a cut piece of cloth.
Proof-of-concept prototype. A first sewn garment in plain fabric, made to test fit and pressure before any money went into printing.
Custom print development. Original repeating patterns laid out and printed on the fabric so the artwork lines up across panels and seams.
High-fidelity prototypes. Finished, wearable samples in several colourways for fit testing, photography and buyer conversations.

Plain black Kool Pressions compression legging proof-of-concept prototype laid flat on a workbench — The first sewn prototype in undyed stock.

Stack of early Kool Pressions fabric prototypes in black, maroon and grey heather — The first sewn prototype in undyed stock.

Engineering the Compression

Compression in a knit garment is not a setting — it is the product of fabric modulus, how far that fabric is stretched when worn, and how the pattern is graded. We picked knits with the stretch and, more importantly, the recovery to hold pressure through a day rather than relaxing after an hour, then worked backwards from the pressure Rhonda wanted at the calf and thigh to the amount each pattern piece is reduced relative to the body measurement.

Seams were placed to avoid the pressure ridges that make compression wear uncomfortable, and the stirrup cuff was shaped so the tension that keeps the legging down is carried across the arch rather than concentrated at the heel. The same approach we use for a mechanical assembly applies here: identify the load, choose the material for it, and let the geometry distribute it.

Custom Prints and High-Fidelity Prototypes

With fit and pressure settled, the prints could be developed against a pattern that was no longer moving. Each artwork was laid out to the cut pieces so the repeat reads correctly on the leg and does not break awkwardly at the seams — the difference between a printed legging and a printed garment. We then produced high-fidelity prototypes in several colourways: a clothing prototype sewn and finished to the standard a buyer would expect off a shelf, not a fitting mock-up.

Design visualisation of a model wearing the multi-colour patterned Kool Pressions stirrup compression legging — The multi-colour print colourway.

Design visualisation of a model wearing the grey and black patterned Kool Pressions stirrup legging — The multi-colour print colourway.

Why an Engineering Firm Took On a Soft-Goods Project

This is not our usual work, and we will say so plainly: LA NPDT's core is mechanical and electromechanical devices — enclosures, mechanisms, circuitry and the low-volume manufacturing behind them. Kool Pressions was a deliberate stretch into a capability we hold but rarely advertise, run by the same engineering team in Ruston, Louisiana that develops our hardware projects. Rhonda's concept was patent pending during the work, so the prototypes had to match the filed design (USPTO patent process overview).

It worked because the problem was an engineering problem wearing fabric. Specifying a pressure, choosing a material by its stress–strain behaviour, prototyping to settle an argument, then holding a design still long enough to invest in tooling — in this case print files and printed fabric rather than moulds — is the same development process we run on hardware. Inventors with soft-goods concepts are usually choosing between a fashion studio that cannot engineer and an engineering firm that will not sew. We can do both, when the concept has a functional requirement at its centre.

Close-up of the Kool Pressions stirrup cuff showing the exposed heel and toe opening on the printed compression legging — The stirrup cuff: the detail that keeps the legging under tension while leaving toes and heels free.

The Outcome

Rhonda left with wearable, photographable, patent-pending prototypes in multiple colourways — enough to test the concept with real wearers, shoot marketing imagery and hold a serious conversation with a manufacturer, without committing to a production run first. That is the whole point of prototyping: buy certainty before you buy inventory. If you have a garment or soft-goods concept with a functional requirement at its centre, talk to our team in Ruston, Louisiana — and see how the same process runs on hardware across our product development portfolio.

Capabilities used on this project

Rapid prototyping services
3D printing, CNC machining, urethane casting and functional prototype builds with published materials, tolerances and lead times.
Low-volume manufacturing
Bridge tooling, short-run production and supplier management for first commercial batches.
Electronic design and PCB engineering
Schematic capture, PCB layout, firmware and electromechanical integration for connected hardware.

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Project snapshot

The Brief: Compression That Someone Would Actually Want to Wear

Engineering the Compression

Custom Prints and High-Fidelity Prototypes

Why an Engineering Firm Took On a Soft-Goods Project

The Outcome

Capabilities used on this project

Rapid prototyping services

Low-volume manufacturing

Electronic design and PCB engineering

IoT Product Development Services: Sysdyne Delivery Sensor

A New Era in Natural Skincare Products

Revolutionizing Shaving with a Waterproof Electric Razor

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