Standard materials are MDF, moisture-resistant MDF and structural plywood. Material choice affects edge appearance, strength direction, finishing effort, moisture response, fit and cost. Choose from the part’s job and finish—not from the material name alone. The exact sheet and grade must be confirmed for each project. The maximum stock size is 1220 × 1220 mm, with a smaller usable cutting area required for workholding and safe edge clearance.
Working comparison
| Material family | Often considered when | Questions to resolve |
|---|---|---|
| MDF | Consistent faces and painted or veneered concepts | Edge finishing, moisture exposure, fixings and weight |
| Moisture-resistant MDF | Humidity resistance is relevant | Exact grade, environment, finish and the fact that “MR” is not waterproof |
| Structural plywood | Layered edge and directional sheet behaviour may suit the design | Grade, face quality, voids, grain direction, flatness and finish |
This table is educational. It does not confirm the grade in stock or fitness for a regulated, structural, wet, food-contact or child-use application.
Detailed material guides
- MDF for CNC-routed parts covers face and edge differences, painted concepts, fixings, finish and moisture limits.
- Moisture-resistant MDF explains why improved moisture resistance is not the same as waterproof performance.
- Structural plywood covers face grade, grain, layered edges, thickness variation and the limits of a structural panel designation.
Nominal thickness is not a fit dimension
A labelled sheet thickness can differ from its measured value, and finish may add more material. Slots, rebates and mating components should be designed around actual stock or a test coupon when fit matters. Read about sheet variation.
Faces, edges and orientation
Mark the visible face and grain direction where relevant. Add arrows and part IDs to the drawing so mirrored plywood parts cannot be nested with the wrong face showing. Plywood can show different face quality and a layered edge; MDF edges usually need different finishing attention from its faces.
Compare the completed product, not raw samples alone
A raw material swatch cannot show every routed edge, pocket, coating or joint. Prepare representative geometry when appearance or fit is commercially important, then carry it through the seller’s real sanding and finish process. Photograph the approved condition under useful light and record the exact board source. This prevents a later reorder from substituting another panel merely because its generic material name matches.
Evidence for a material recommendation
Part function, environment, desired appearance, finish plan, hardware, nominal thickness preference, critical fits and whether a particular manufacturer/grade is required.
Comparing materials for a painted display
A painted display might use MDF, MR MDF or plywood, but its exposed edge, fitted slot and indoor environment make each material behave differently. Compare the real board and intended finish before fixing the slot fit or appearance requirement.
Choose material from the finished requirement
| Decision | Evidence to use | Consequence |
|---|---|---|
| Environment | Describe humidity, contact and maintenance accurately. | A material label is not expanded into an unsupported wet-use claim. |
| Appearance | Choose smooth painted face, layered edge or another verified result. | The final finish drives the sample needed. |
| Fit | Measure actual sheet and include finish build. | Nominal thickness is not copied into the slot. |
| Source control | Name product/grade when it matters. | Repeat orders do not substitute a visually similar board silently. |
Material assumptions that cause poor results
Material is selected from a small website swatch.
Use representative physical samples and current datasheets for face, edge and application decisions.
MR becomes waterproof in seller copy.
Keep product wording inside the manufacturer’s scope and completed finish evidence.
Structural plywood becomes a product load guarantee.
Separate panel classification from joint, fixing and finished-product engineering.
Finish responsibility is absent from the quote.
Name who prepares edges, coats, assembles and inspects the final result.
Material-selection checklist
- State intended use and environment.
- Name desired face and edge appearance.
- Identify visible face and grain.
- Provide exact grade if mandatory.
- Mark fitted features and actual stock.
- Describe finish system.
- List hardware and fixings.
- Define acceptable natural variation.
- Control substitutions.
- Review parcel weight and protection.
Material questions
Which material is cheapest?
A board price alone is not enough; include machining, edge preparation, finish, waste, weight and product suitability.
Can nominal thickness be used for joints?
Not when fit matters. Measure representative stock and test the finish condition.
Does Wood to Spec certify my chosen material?
No. The review addresses confirmed machining scope; product suitability and regulated claims remain separate responsibilities.
Confirm the exact board and supply route
Use current manufacturer or supplier information for the exact board. The quotation confirms stock availability, thickness, whether Wood to Spec or the customer supplies the material, the machining operations and the included production stages.
Ask for a material review
Ask for a material-and-feature review. Also plan sanding, painting and finish access.