On Running scales its spray-on ‘Hyper-Foam’ shoe: what it means for runners and footwear

Background

The sneaker industry has a habit of turning manufacturing breakthroughs into marketing moments—think knitted uppers, printed midsoles, air bags you can see, and carbon plates you can feel. Swiss shoemaker On has built its identity on visible geometry and resilient foams, but its latest move shifts the innovation spotlight from the sole to the upper. The company is taking a lab-born technique—spraying a reactive “hyper-foam” directly onto a form—to create a seamless toe box that stretches, grips, and holds shape without traditional layers, stitches, or laces.

That concept isn’t a sci-fi gag. Sprayed textiles have floated around fashion for decades, and footwear brands have experimented with fused films and molded cages. What’s different here is the practical promise: a single-piece, spray-formed forefoot bonded to a conventional midfoot and sole, sold at scale as a running shoe you can actually wear outside the lab.

The model at the center of this shift is the LightSpray Cloudmaster 3 Hyper (On’s naming signals both the spray process and the company’s higher-rebound foam family). It’s a laceless design with an elastic, one-piece toe box formed by controlled deposition of a foam onto a last—essentially a foot-shaped mold—before assembly. If the scale-up works as advertised, it compresses several steps of upper-making into one repeatable operation.

Why this is notable:

Uppers—everything above the sole—usually require multiple panels, reinforcements, eyelets, linings, and glue. A spray-formed shell collapses those into a single part around the forefoot.
Fit and stretch can be fine-tuned by adjusting spray thickness and timing across zones.
Material use is easier to meter than cutting panels from sheets, which can reduce waste.

What happened

On is moving the LightSpray Cloudmaster 3 Hyper from small, controlled runs toward wider commercial availability. The shoe replaces a traditional multi-panel forefoot with a seamless, spray-formed toe box that doubles as structure and stretch. The rest of the package looks like a modern On trainer: a lightweight chassis, a cushioned midsole built around the brand’s signature hollow “cloud” geometry, and a rubberized outsole.

Instead of laces, the upper relies on engineered stretch and a tighter midfoot wrap to lock the foot. The spray-formed forefoot functions as both a breathable casing and an adaptive band; it flexes under load, returns to shape, and interfaces directly with more conventional textiles along the quarter and tongue area.

Behind the scenes, the company has tuned manufacturing cells to apply its “hyper-foam” in a controlled way—adjusting deposition rate, dwell time, and cure to achieve the right blend of softness and rebound. The word “hyper” in On’s recent lineup typically denotes higher-energy foams with faster rebound; in this context, the spray is part of the upper rather than the midsole, but shares the same chemical family and elastic character. That continuity matters for comfort and durability: the sprayed toe box needs to flex thousands of times without cracking or delaminating.

Scaling this process is nontrivial. Unlike knit uppers (which can be produced by the million on established flatbed machines), sprayed structures demand:

Tight process control to ensure even thickness across curved surfaces.
Worker and environmental safety protocols to handle reactive foams and solvents (or solvent-free chemistries if used).
New quality checks: peel strength, tear propagation at flex points, and long-term UV and sweat resistance.

On’s announcement signals those hurdles are being addressed well enough to move beyond concept drops into broader retail. Expect colorways and sizes to expand as factories gain confidence with yield, cycle times, and defect rates.

How the spray-formed toe box works (and why it’s different)

A conventional running shoe upper is a sandwich:

Outer layer: woven or knit textile with synthetic overlays for durability.
Middle: films and reinforcements that create structure and eyelet rows.
Inner: lining or bootie for comfort.

Each piece must be cut, stitched, placed, and glued—steps that add time, labor, and waste. The LightSpray approach aims to skip the cutting-and-stitching stack in the forefoot by forming the shell directly onto a last. In simplified terms:

A last is prepped with release agents and masking to define zones.
A reactive foam (likely a TPU- or polyolefin-based chemistry, potentially waterborne or solvent-free) is atomized and deposited in controlled passes.
The material gels and cures, fusing into a continuous, elastic skin with tunable thickness.
The shell is demolded, trimmed, and integrated with a collar/midfoot assembly, then mounted to the midsole/outsole platform.

The benefits:

Fewer seams: Seams are failure points; removing them in the toe box reduces risk of rips and hotspots.
Zoned performance: The sprayer can lay down thicker ribs over the big toe for protection and thinner films over the vamp for flex and breathability.
Precision metering: Only the necessary grams are sprayed, reducing offcut waste compared with patterned textiles.

The trade-offs to watch:

Breathability: Knit is naturally porous; a sprayed film needs microperforation or inherent porosity to match airflow.
Surface durability: Sprayed skins must resist scuffs and toe drag without becoming shiny, brittle, or sticky.
Repairability: A monolithic shell can be hard to restitch; field repair may rely on patches or heat-fuse kits.

Why a laceless design?

Laces are adjustable, cheap, and familiar—but they also force pattern complexity (eyelets, reinforcements) and add local pressure points. A laceless upper with enough elasticity can:

Evenly distribute tension across the midfoot.
Speed entry/exit for daily trainers and travel.
Reduce hardware and adhesives around the throat of the shoe.

That said, no-lace designs must thread the needle between hold and comfort; too loose and you get heel slip, too tight and the instep protests on long runs. On appears to be using a higher-tension saddle around the midfoot with the spray-formed toe box acting as a compliant shell. Expect a learning curve on sizing as buyers calibrate their preferred tension without the crutch of lace adjustment.

How this fits into footwear’s broader tech arc

The LightSpray project sits alongside a decade of manufacturing pivots:

Knit-to-shape uppers (Nike Flyknit, Adidas Primeknit) cut waste by knitting only the needed areas and reduce seam count.
Fused film and thermoforming simplified support overlays and toe caps.
3D-printed midsoles (Adidas Futurecraft 4D, lattice TPU platforms) aimed to tailor cushioning through geometry.
Supercritical foams (PEBA-based or nitrogen-infused EVA blends) boosted rebound and durability in midsoles.

Spray-forming an upper adds another knob for engineers: rather than only choosing yarns and stitch patterns, they can “paint” structural properties where they want them. If the process matures, it could coexist with knit—spray the outer shell over a minimal knit sock, for example, to gain durability without losing breathability.

Sustainability lens: promise, pitfalls, and the messy middle

Every footwear brand promises sustainability; not all innovations move the needle. Spray-formed uppers offer some tangible advantages, with caveats:

Potential wins

Less scrap: No panel cutting means fewer offcuts headed to the bin.
Fewer materials: Eliminating secondary reinforcements and eyelet stays reduces bill-of-materials complexity.
Energy/time savings: Fewer stitching operations can shrink energy use per pair and shorten supply chains.

Questions to track

Chemistry: Are the sprayed foams waterborne or solvent-free? What’s the VOC profile, and how are emissions controlled on the line?
Disassembly: If the toe box bonds to a different midfoot textile and a TPU or EVA midsole, can the shoe be separated for recycling, or is it another multi-material dead end?
Repair and longevity: A durable shell that extends shoe life may do more environmental good than theoretical recyclability that never happens.

On has public sustainability goals and has tested subscription and recycling pilots in the past. Applying those lessons here—clear repair policies, spare insole availability, and end-of-life channels—will matter as much as the spray tech itself.

Fit, comfort, and performance expectations

Without laces, fit becomes the headline. Runners should expect:

A snugger midfoot: The shoe may feel locked in without overt pressure; if your instep is high, initial on-foot feel will determine compatibility.
Adaptive forefoot: The sprayed shell should flex predictably; toe splay may feel slightly more contained than in open knits but more forgiving than stiff toe caps.
Stable platform: On’s midsole geometry typically balances softness with a guided ride; pairing that with a secure upper prevents foot slosh on corners.

Use cases

Daily training and travel: Easy on/off and resilient foam make sense for commutes, errands, and steady miles.
Tempo-ish efforts: If the midsole uses a higher-energy formulation, it may double as a lightweight trainer for moderate paces.
Not a trail shoe: Until abrasion and debris management are proven, technical trails are a stretch.

What it means for factories and cost

Scaling a new process forces factories to retool, retrain, and rethink quality. Key implications:

Capital and cells: Dedicated spray booths with precise robots or guided manual rigs, plus curing zones, add up-front cost but can cut sewing lines.
Yield focus: Early runs will chase consistency; over- or under-sprayed shells become waste. Expect gradual improvement and tighter tolerances over quarters, not weeks.
Pricing: Novel processes debut at premium price points; costs can drop as throughput climbs and scrap falls. Don’t be surprised if the LightSpray variant sits above On’s traditional daily trainers at launch.

Risks and open questions

Long-term durability: How does the shell handle repeated toe flex in winter cold, summer heat, and sweat salt? Early adopters will be the test bed.
Breathability balance: Can On match knit-level airflow without sacrificing the protective feel that a shell offers?
Sizing and inclusivity: Laceless designs can be brilliant for some feet and unforgiving for others. Half sizes and multiple widths would help, but complicate production.
Repair ecosystem: Will On offer patch kits or in-store repairs for scuffs and small tears? That would boost confidence and circularity.

Key takeaways

On is scaling a laceless running shoe with a single-piece, spray-formed toe box—compressing multiple upper-making steps into one process.
The technique promises lower waste, fewer seams, and tunable fit characteristics, but must prove durability and breathability in real-world use.
Expect premium pricing at first, a sizing learning curve, and iterative improvements as factories refine yield and consistency.
If successful, spray-forming could join knit, fused films, and printed midsoles as a mainstream tool in the footwear manufacturing kit.

What to watch next

Real-world wear data: Look for third-party durability tests and long-term user reviews, especially about toe creasing, peeling, and odor control.
Expanded runs: More sizes, widths, and colorways would indicate manufacturing confidence and lower defect rates.
Cross-category adoption: If the process appears in lifestyle, hiking, or court silhouettes, it’s more than a niche play.
Sustainability receipts: Transparent chemistries, VOC disclosures, and end-of-life pathways will separate substantive progress from green gloss.
Competitor response: Expect rival brands to counter with their own sprayed, cast, or molded upper experiments—or to double down on knit-plus-films approaches.

FAQ

Is the sprayed toe box breathable?
- It should be more breathable than a solid rubberized toe cap but likely less airy than open knit. Look for microperforations or mesh-backed zones in production pairs.
Will it stretch out over time without laces?
- High-quality elastomers can retain shape well, but all textiles and foams relax slightly. Expect a break-in period and gradual settling rather than dramatic stretch.
What if the shell scuffs or peels?
- Surface scuffs are cosmetic. Peeling at bonded seams is a warranty issue. Patch kits or heat-fuse repairs would be welcome; check On’s support policies at launch.
How do I pick a size in a laceless shoe?
- Start with your standard running size. If you’re between sizes or have a high instep, try in-store. The midfoot wrap should feel snug but not numb; toes should wiggle without pressure.
Is this actually greener than a regular upper?
- Likely greener on material waste and part count. The total footprint depends on chemistry, energy use, and end-of-life options. Ask for VOC details and recycling pathways.
Who is this for?
- Runners and everyday wearers who value easy entry, a clean look, and a secure midfoot. If you need on-the-fly adjustability or use orthotics with varied volume, test fit first.

Source & original reading

https://www.wired.com/story/on-lightspray-cloudmaster-3-hyper/

On’s Spray‑On “Hyper-Foam” Shoes Move From Lab Trick to Real Production