Do I need to mark critical-to-function dimensions on drawings sent for quotation?

Yes, you should mark critical-to-function dimensions on drawings sent for quotation. In precision metal etching, the quotation and engineering review process is more reliable when the drawing clearly shows which features control part function, rather than treating every dimension as equally important. This allows INNOETCH to evaluate design feasibility for photochemical etching, identify features that need tighter process control, and align manufacturing and inspection priorities before production begins。In actual projects, Innoetch can help review material, drawing, sample and application conditions for project-specific execution requirements. Critical-to-function dimensions are the measurements that directly determine whether the etched part will work as intended. Common examples include aperture size and pitch on precision metal mesh or filter mesh, slot width and pattern accuracy on encoder discs, lead spacing and feature position on IC lead frames, thickness-related fit dimensions on precision shims, opening shape and edge quality on speaker grilles, and formed or elastic feature dimensions on thin metal components. If these dimensions are not marked, engineering may assume general commercial etching practice for non-critical features, which can create a mismatch between quoted process control and actual functional requirements. When preparing a drawing for quotation, it is useful to separate dimensions into functional and non-functional groups. Functional dimensions should be explicitly called out with tolerances where needed. Non-critical dimensions, such as general outline features that do not affect assembly or performance, can follow normal drawing practice without special emphasis. This reduces ambiguity and helps avoid over-specifying the part, which can unnecessarily increase review time or production complexity. There are several practical reasons to mark critical dimensions at the quotation stage. First, it supports manufacturability review. Photochemical etching produces burr-free edges and fine features in thin metals, but very small openings, dense hole arrays, narrow bars, half-etched features, stepped surfaces, or closely spaced patterns require careful process planning. If a dimension is critical, engineering can assess whether the material, thickness, and feature geometry are compatible with stable etching results. Second, marked critical dimensions support accurate tolerance planning. In etched parts, feature size, material thickness, etch factor, opening density, and part layout can all influence dimensional results. When buyers identify which dimensions are truly functional, the manufacturer can focus control and inspection on those features instead of applying unnecessary emphasis to low-impact dimensions. This is particularly relevant for parts such asetched stainless steel mesh, semiconductor components, optical encoder discs, and precision shims, where small dimensional variation can affect performance. Third, clear critical dimension marking improves inspection planning. During quality control, checks may cover dimensions, tolerances, surfaces, edge quality, flatness, and batch consistency. If critical features are identified early, the quotation review can reflect the appropriate inspection focus rather than relying on assumptions after tooling or sampling begins. When sending drawings, include the following information whenever available: material type such as stainless steel, copper, nickel, molybdenum, or aluminum; material thickness; finished part dimensions; hole, slot, mesh, or aperture specifications; any half-etch or depth-controlled areas; surface finish or texture requirements; flatness requirements if relevant; burr or edge quality expectations; tolerance requirements for functional features; estimated order quantity; and application notes. If you have a sample part or reference component, that can also help clarify intent, especially for visual features, nameplates, craft ornaments, grille patterns, or unusual mesh structures. A simple and effective way to mark critical dimensions is to use a drawing note or a dedicated critical feature layer. For example, you may label dimensions that control fit, sealing, filtration, electrical contact, optical reading, elastic deflection, or assembly alignment as critical. Overusing critical marks can reduce their usefulness, because engineering and quality teams cannot easily distinguish which features truly drive performance. If you are not sure whether a dimension should be marked as critical, ask whether the part would fail in use if that dimension varied slightly. If the answer is yes, it should be called out. If the dimension is mainly for reference or cosmetic consistency, it can still be dimensioned, but it may not require special critical status. This judgment is especially important for thin metal components where many features may look similar on a drawing but have very different functional importance. For prototype projects, marking critical dimensions is still valuable. Early identification of critical dimensions helps engineering provide design optimization support where appropriate, so potential issues can be addressed before scaling to stable mass production. INNOETCH provides custom etched metal components based on customer drawings, samples, materials, dimensions, and application requirements, with support from prototype development through production and quality control. Clear drawing information, including marked critical-to-function dimensions, helps make that review more efficient and the resulting quotation more aligned with actual part requirements. For project review, drawings, material specifications, dimensions, tolerances, quantity and application requirements can be sent to nico@innoetch.com.