Rough-Sawn Board Varies in Thickness? Map a Focus Strip
Measure a cross-grain height strip at fixed stations before placing artwork on rough-sawn stock. Distinguish local texture from a broad crown; one center focus reading can miss both.
One center reading hides the surface
Rough-sawn stock can change height across a sign even when its overall board dimensions fit the workspace.
Observation: station C is 1.1 mm above A while station D contains isolated ridges another 0.7 mm higher. Controlled test: plot peaks and representative valleys at five equal stations and repeat after rotating the board on the same support. Interpretation: a smooth curve that rotates with the board is crown; sharp local peaks are texture. Action: move fine detail, prepare the surface, or reject the region.
Plot five cross-grain stations
| Station | Record | Artwork consequence |
|---|---|---|
| A: left edge | Peak and valley height | Keep fine text away from severe texture |
| B: left-center | Mean surface and crown trend | Check focus evidence |
| C: center | Reference height | Do not treat as the whole board |
| D: right-center | Trend reversal or knot | Move critical detail |
| E: right edge | Edge lift and support | Fixture review |
| Texture peak note | Highest isolated ridge outside station means | Keep critical stroke away or prepare surface |
Keep the strip map with the board photograph. If the board is flipped or rotated, the station labels must move with it.
Crown and texture produce different traces
- Acclimate and identify the final visible face.
- Lay a removable strip across the intended artwork path.
- Measure peaks and representative valleys at equal spacing.
- Plot the values; a gradual curve suggests crown, abrupt jumps suggest texture or defect.
- Frame the artwork only after the chosen region fits the proven height range.
Do not average away the highest ridge. The strip should show both the broad surface trend and local clearance risk. A worked plot might read A 0.0, B +0.4, C +1.1, D +0.6 with +0.7 texture, E +0.1 mm. That trace tells a different story from a single mean of +0.44 mm.
Place fine detail in the qualified band
Attach the cross-grain strip to the board photo before file placement. Rotation or face changes invalidate the station map.
Confirm the active X1S configuration on the X1S 2026 page. Before assigning visible letters to the measured surface, Map Sheet Defects Before Nesting Visible and Hidden Parts helps reserve clear regions.
Questions about texture, sanding, and focus
Can deeper engraving hide uneven focus?
It can worsen char and still leave inconsistent detail. Geometry should be qualified first.
Should I sand the board flat?
Only if that matches the promised rustic finish and removes enough variation without exposing defects.
Can I average all readings?
An average can hide a single high station that controls clearance or focus.
Place artwork on the trace, not the average
Keep fine strokes inside the qualified height band and away from isolated peaks. If the face changes, make a fresh strip.
