Reading the dressed surface
How to judge a dressed stone face by sight, touch and straightedge, including texture, drafted margins, grain and the signs of a finished face.
A dressed face is read with the eye, the fingertips and a straightedge. The eye picks up texture and light, the hand finds high spots and hollows, and the straightedge shows whether the face is flat along a line. Using all three gives a clearer picture than any one alone.
What the texture shows
Each tool leaves its own signature. Point work shows pits of uneven size. Claw work shows fine parallel ridges that run in the direction of the stroke. Tooth work shows a finer, more even grain with the ridges nearly gone. When a face carries a mix of marks, the work is not finished, and the earlier tool has left high spots the later one has not yet reached.
Checking flatness
- Lay a straightedge along the face in several directions, across and on the diagonal.
- Hold it against the light and look for a gap between the edge and the stone.
- Run the flat of a hand over the face to feel any ridge the eye misses.
- Mark the high spots in chalk and return to them with the tooth chisel.
A twist in a face is harder to see than a hollow. Two straight strips laid at opposite ends of a face can show it: sight across their top edges, and if the lines do not match, the face twists between them.
The drafted margin
A drafted margin is a narrow, smooth strip cut along one edge of a face. It serves as a true reference line, and the rest of the face is judged against it. The margin should run straight along its length and meet the next face in a sharp corner. A margin that drifts shows that the reference was lost during earlier passes.
Grain and bed
The bed is the layering plane in sedimentary stone, and most such stone splits more easily along it. Grain is the directional character of the stone. Working across the bed or against the grain takes more effort and can leave a rougher edge. Reading the stone before striking lets the work follow the way it naturally breaks. The toolkit page lists which tool suits each stage.
Signs of a finished face
- The straightedge lies flat in every direction without rocking
- The texture is even across the whole face
- The drafted margin is straight and sharp at the corner
- No fresh chips show near the edge or the marked lines
If the checks show a face is not ready, go back to the stage that left the fault, as set out in roughing out a block. The block should also sit steady while it is checked, which is covered in setting up a stable work surface.