A resin prototype that comes back warped, chalky, or scarred on the one face that seals against a gasket costs more than the part: it costs the review meeting, the test slot, and a second round of approvals. The specification you send with an SLA 3D printing service decides most of that outcome. This guide

A clear resin part is judged the moment it is held up to a light, and that judgement is unforgiving: a single unpolished face, a trapped bubble, or a support scar on the viewing surface is visible from across the room. Transparent resin 3D printing is less about which resin is ordered and more about

A nylon bracket that passed a bench test can still fail in the field if it was built in the wrong orientation, and a part that measured correctly on the first order can arrive noticeably different on the fifth. Powder-bed nylon is one of the few additive routes that carries real service loads, which is

The first SLS part a team receives usually triggers the same two questions: why does it feel like fine sandpaper, and why does a hole that measured correctly on the drawing come back undersized? Neither is a production error. Powder-bed nylon has a characteristic surface and a set of geometric limits, and both are predictable

Choosing a powder by name is how projects end up with a part that is stiff where it needed to bend, or brittle where it needed to hold a thread. Selective laser sintering materials are a small family with large behavioural differences, and the choice changes the design rules, the finishing steps, and the price

A metal additive part that arrives distorted, with supports fused into a sealing face, is not a process failure: it is the predictable result of a build that was orientated before anyone decided which faces mattered. Laser powder bed fusion is now a production route for impellers, manifolds, heat exchangers, brackets and tooling inserts, and

Two acronyms, one machine family, and a specification conversation that often goes nowhere useful. Engineers comparing DMLS and SLM usually already know that both melt metal powder with a laser; what they need is the set of decisions that actually differ on a purchase order, and the language to compare two quotes without being misled

A material change on a powder-bed part is not a swap of equivalent options. Moving from PA12 to PA11 changes how the part behaves in a drop test; moving to an elastomeric powder changes how thick the walls need to be; and dyeing a batch produces a colour that depends on the powder beneath it.

Both processes build nylon parts in a powder bed, both produce functional components without supports, and both are quoted from the same STEP file. The differences that matter appear in the third batch, not in the first: a surface that repeats identically, a dimension that stays inside its callout across the bed, and a price

The question usually arrives with a part already designed: a bracket, a housing or a fluid component in metal, and an assumption that one of the two processes is obviously right. On simple geometry the answer is machining, because a machined face holds a tolerance that an as-built powder bed surface does not. On geometry