Injection-moulded from ABS plastic — the same family of materials used in LEGO bricks. ABS does not warp, holds its shape over time, and bonds reliably with superglue (cyanoacrylate) and two-part epoxy. The textured top surface grips PVA, texture paste, and basing sand without needing to score or rough up the surface first. Takes all spray and brush-on primers cleanly.

Every mould in the OBS range is designed in-house using industry-standard CAD — these are not generic imports. We control the full production chain from design through to quality control. Mould lines are clean and consistent.

At 100mm, this is the largest square base in the OBS range. The 1.32mm floor and 4mm total height keep the profile low while maintaining rigidity under heavy kits. 2.7mm of underside clearance fits 5x2mm disc magnets — at this size use four or more spread in a square pattern for a balanced, secure hold in transport.

100mm square is used for the largest war machines, greater monsters, and centrepiece models in mass-battle fantasy and historical wargaming. Correct for organised and competitive play in systems that specify a 100mm square footprint.

The 99.51mm outer width matches industry-standard 100mm nominal sizing with a fraction of clearance for ranked placement. This is the largest square base in the OBS range.

Part of the Open Basing System (OBS)

One Ecosystem · Every Size · Every Shape

OBS is a modular basing ecosystem designed as a whole — not a random collection of bestsellers. Every size, shape, converter, and tray is planned to work together. Independent and gamer-built.

New products added regularly — the OBS range is always growing.

At 100mm you're mounting large war machines and heavy resin kits. Pin every contact point with 1mm+ brass rod and two-part epoxy — CA alone won't hold long-term at this weight. For kits with small contact points, build structural scenic elements and pin through those as hidden supports.

Nearly 100 cm² — treat it like a diorama. Plan the composition before committing: mock up the model, sketch terrain placement, consider how the base sits in formation alongside smaller ranked units. Build elevation with cork and bark, add environmental detail. Keep the bevel edge clean for formation alignment.

Wash before priming — a quick rinse in warm soapy water removes mould release residue. Let it dry completely flat before spraying.

2.7mm underside clearance fits 5x2mm disc magnets. Use four or more spread in a square pattern for a balanced hold — essential for heavy models in transport. CA gel, check polarity before it sets.