Product Design 


Skia Sweet Spot Ski Trainer


We helped Start-up Company SkiA develop their launch product from an initial idea for a “dry-land” based ski training aid to a production reality.


The trainers fit onto all sizes of ski boot and help users learn essential balance skills that improve turning efficiency and develop better skiing technique. They include a series of different sized balance blocks that provide increasingly difficult challenges to teach perfect posture, promote dynamic movement and guide centred pivoting.


The Foot Plate component design cleverly combines a rigid platform with flexible sections that adjust to the shape of any boot.


We developed the design from initial concepts, through test rigs and fully detailed 3D CAD models to working SLS prototypes for extensive performance testing. We designed the product packaging and sourced, supplied and managed manufacture of the production tooling and finished boxed products from our network of Far East partners.


"Design 4 Plastics have been absolutely integral to the development of our first product. Quite simply, the SkiA Sweetspot Trainer would not have happened without them"

SkiA Company Founder.

Skia early concept sketching

Our Initial Concept Designs explored different options for how to achieve the variable difficulty balance challenge and how to attach the Trainer to the Ski Boot.

Skia functional test prototpyes

We created a series Functional Test Prototypes to develop the fit with the large range of Ski Boot sizes and to gauge the level of difficulty of the balance challenge.

Skia CAD Development of prototypes

Having proven the functional principles we developed the design detail in 3D CAD. One challenge was to provide sufficient adjustability to cater for the large range of Ski Boot sizes. The flexible side sections of our Foot Plate design allow the Trainer to fit to any boot.

Functional SLS prototypes of CAD for testing

A small batch of SLS prototypes were built for extensive performance testing in a live Ski School training environment. Feedback from these sessions led to further design enhancements.

Maxwell render of Skia Ski Trainer

Photo Realistic Rendering of our production level 3D CAD models.

Manufacture and Packaging of the Skia Ski Trainer

Design 4 Plastics managed the entire process of realizing the product into production. We sourced suitable manufacturers and assessed all pre-production moulded and riveted samples, printed labels, user manuals and packaging for final quality approval prior to supplying complete finished product.

Rocol Easyline edge Line Marker

Photo Realistic Rendering of our production level 3D CAD assembly.

Line marking applicator testing

We created alternative concepts for producing sharp edged sprayed lines and experimented with these in our workshop to find the best way of controlling paint over spray on the move. This led us to the novel idea of introducing airflow that blows stray drips into the wet line to eliminate fuzzy edges. This proved to be a patentable feature.

Easyline edge CAD development

Once the basic function was proven we produced the first 3D CAD assembly including all the features agreed from the Concept stage. Appropriate manufacturing processes were considered to ensure the parts could be made economically.

Easyline edge spray nozzle

Evaluating the geometry of the spray nozzle posed one of the biggest challenges of the project. The accuracy demands of the orifice, material and surface finish were impossible to achieve by conventional prototyping techniques. We used a prototype injection mould tool to fine tune and prove the design.

Easyline prototype

We employed SLS Nylon to build the first fully working prototype. This was used to test and develop the function of the Line Marker and underwent many changes to refine the performance.

Easyline edge protective case.

We sourced and managed production of all tooling for the project and were responsible for checking the first off samples. This included approving mould drawings and final tooling adjustments. We rigorously inspected the initial batches of finished products to ensure a smooth introduction to market.

Easyline Edge Line Marking System

Starting with an open brief to develop a replacement for ITW ROCOL’s aerosol spray line applicator we came up with an innovative, patented solution that offers many advantages over anything else on the market.

Easyline Edge can produce 50, 75 or 100mm wide lines from a single aerosol can thanks to our clever spray nozzle design and easily variable applicator geometry. The lines produced are kept clean and crisp with replaceable spray masks and a battery powered airflow system that directs paint over-spray back within the line. The handle adjusts to suit the user and the rear legs can be folded in to allow marking close to walls and racking.

We developed the design from concepts, through test rigs, fully detailed 3D CAD models, rapid prototypes and development injection mould tools to fine tune the spray nozzle. We managed manufacture of all the injection mould tools and product assembly for the initial production batches.

“The team at Design 4 have helped us create the market leading product in Line Marking, massively increasing our sales”

ROCOL site safety  product manager.


Rainwater Terrace water butt is a new concept in rainwater collection promoting the reuse of valuable rainwater and “grow your own” sustainability.

The unique patented modular design has distinct advantages over other water butts on the market. Rainwater Terrace® not only saves the householder money by reusing rainwater in the garden, its unique integrated plant growing system makes it an attractive addition to any home.

Transportation is not an issue as all the parts nest within each other creating a compact package that’s easily transportable in a small car.

The Rainwater Terrace® is built to last. Injection moulded in heavy gauge UV stable plastic, these strong durable components have excellent impact strength and are manufactured to perform in all weather conditions. Requiring no special tools or complicated plumbing Rainwater Terrace® is very simple and quick to install.

Located above ground it can be installed on completion of a new-build and requires very little maintenance (If any!). There are many rainwater collection systems on the market; none have the finesse and visual impact of the Rainwater Terrace®

Rainwater Terrace water butt comes in 4 sizes/colours including black, black/dark green black/bright green and black/duckegg blue

Rainwater Terrace water butts come in a range of sizes and colours to suit the space available.

134 Litre Rainwater Terrace water butt

The new Rainwater Terrace water butt with detachable self watering planters. Shown in duckegg blue

Rainwater Terrace water butt collection

The Rainwater Terrace water butt is modular and comes in a range of sizes that can be configured to suit the space available.

Rainwater Terrace water butt development

The Rainwater Terrace water butt has been designed & developed by design 4. It is manufactured and sold in the UK.

Black water butt with planters

The 3 tier 200 litre Rainwater Terrace water butt with planters.

Self watering water butt planters

The Rainwater Terrace water butt uses clever wicks to water the planters with some of the rainwater collected.

How a Rainwater Terrace works

Rainwater Terrace water butt has a through flow system that ensures the Rainwater collected stays fresh.

Water butt on a patio

Rainwater Terrace water butt is designed so that it does not need to be hidden away.

Water butt planter

The Rainwater Terrace planters are perfect for herbs or flowers.

Nesting water butt packs down

The Rainwater Terrace water butt packs down to less the half of its assembled size.

Water butt with herbs

Rainwater Terrace water butts are great for growing herbs and salad vegetables when you are short of space.