Choosing a chemical etching / photochemical machining (PCM) supplier is less about finding ‘who can etch’ and more about finding who can repeatably hit your critical features, document quality properly, and support you from prototype through production.
This guide walks through the practical factors that matter when choosing a photo chemical machining (PCM) supplier. It’s based on what we’ve learned working with design engineers, procurement teams, and project managers across aerospace, medical diagnostics, Formula 1, and other demanding sectors over 35 years.
Start with the decision that matters most: risk or price?
Before you compare suppliers, be clear on what you are optimising for.
If your part sits in a regulated or high-impact system (medical, aerospace, defence, energy), the decision is usually about risk and repeatability. If it’s a low-risk commodity component, cost and lead time can matter more.
A good supplier for your project is the one whose process control, inspection, and communication match your risk level. That is the lens to use for every question that follows.
What to check first (fast shortlist)
1) Can they make your part type, not just ‘do etching’?
Ask what they regularly produce that looks like your application: thin shims, mesh, EMI shielding, apertures, intricate patterns, multi-level etch, or high-count nested sheets.
A supplier can be excellent at one type of etch work and still be the wrong fit for yours. You are looking for proven familiarity with your geometry and tolerance sensitivity.
2) Are they set up for prototypes and production?
Some suppliers are great for prototypes and struggle with stable production. Others are optimised for production and slow for early-stage iteration.
Ask how they handle the transition from prototype to production, including revision control, process locking, and first article inspection.
3) Do they communicate like an engineering partner?
The best suppliers tell you early if something is risky: feature density, material thickness, tolerance stacking, inspection feasibility, or handling requirements.
If a supplier only says ‘yes’ and cannot explain what drives outcomes, that’s a warning sign. You want honest constraints, not confident promises.
The questions procurement should ask (and why)
‘How do you handle traceability and documentation?‘
If you need auditability, you want to know whether the supplier can provide batch traceability, inspection reports, and controlled documentation. This is where “ISO certified” becomes meaningful only if it is backed by what they actually supply per order.
If you require full traceability, say so early. It affects handling, record keeping, and sometimes lead time.
‘What happens when a part is out of tolerance?’
You are not only buying parts, you’re buying how the supplier behaves when something goes wrong.
Ask how they manage non-conformances, what their corrective action process looks like, and how they communicate issues. The answer tells you whether they are a partner or a risk.
‘Do you support design feedback before we commit?’
Engineering teams often learn most from early DFM feedback. A supplier who can quickly highlight risk areas, and suggest changes that protect function, can save weeks of iteration.
This is one of the biggest differentiators between a commodity supplier and a long-term manufacturing partner.
What engineers should clarify before they pick a supplier
Define the critical features, not a blanket tolerance
In chemical etching / PCM, not every dimension behaves the same way. You get better results when you identify the handful of dimensions that really matter to function, then align the process and inspection around them.
If you are not sure what is critical, share the assembly context. A good supplier can help you choose what to control tightly and what can be relaxed.
Be specific about material and thickness
Material type and thickness strongly influence what is practical. If you can, specify the grade and thickness. If you cannot, describe the performance requirement (corrosion resistance, conductivity, spring properties) so the supplier can recommend a starting point.
Flag any cleanliness or handling requirements early
If the parts are used in sensitive assemblies or clean environments, packaging, handling, and contamination limits should be part of the brief, not an afterthought. This can influence finishing, inspection, and packing processes. For context on the process itself, see our explainer.
What to include in your RFQ so you get usable quotes
A common reason supplier selection drags on is vague RFQs. Give suppliers enough clarity to quote accurately and compare like-for-like.
Include:
- Drawing or CAD file with revision control
- Material and thickness, or functional requirement
- Quantity now, and expected future demand
- Critical dimensions and tolerance priorities
- Finishing requirements (plating, passivation, marking, deburr expectations if relevant)
- Packaging and cleanliness requirements
- Any compliance or documentation needs (inspection reports, traceability)
- Target lead time, plus any hard deadlines
If you’re short on time, send what you have and state what is missing. You’ll often get better supplier engagement if you are upfront about the stage you’re at.
Spot the red flags early
These are the common signs a supplier might cost you time later.
- They quote without asking clarifying questions about critical features or inspection
- They promise tight tolerances without explaining what drives them
- They cannot describe how they control repeatability batch-to-batch
- They are vague about documentation, traceability, or what reports they provide
- Communication is slow or unclear during the quoting stage
If the quoting stage feels difficult, production will usually feel worse.
Where NEL fits
If you want an engineering-led partner rather than a quote-only supplier, NEL Technologies supports programmes from feasibility through prototype to production, with clear DFM feedback, defined inspection on critical features, and documentation that stands up to audit. If that’s the level of support you need, explore our PCM capability.
To choose the right chemical etching / PCM supplier, start with your risk level, then shortlist based on proven part experience, process control, inspection capability, and how they handle documentation and change. The best supplier is not the one who says ‘yes’ to everything, it’s the one who can explain constraints clearly and deliver repeatably across prototypes and production runs.
If you want to sense-check feasibility for your component, or if you already have a drawing and basic requirements, you can contact us here.