Sharpening Gravers: Angles and Stones
雕刻刀的磨制与刃角选择
标签：磨刀, 刃角, 油石, 推刀
雕刻刀九成问题出在刃口。磨制流程：先 400 目刚玉油石磨出面（菱形推刀 30°、平口刀 45°、圆弧刀按槽宽定角），再 1000 目精磨，最后在贴 1 μm 金刚石研磨膏的皮革上背刃 5–8 次拉出镜面；刃口毛刺用 30 倍放大镜检查，呈均匀黑线即合格。铜版雕刻推刀以 45° 刃角最通用，硬黄铜与钢模加到 50–55°，软铅版降至 30°。磨刀时刀柄抵肩窝推"8"字、刀面始终贴石；一次磨刀可连续刻 2–3 h，手感发涩立即回磨。
Ninety per cent of graving problems are the edge. Sequence: face the tool on a 400-grit aluminium-oxide stone (30° for diamond-section burins, 45° flats, rounds set by groove width), refine at 1000 grit, then strop 5–8 pulls on leather charged with 1 μm diamond paste; inspect under 30×—a uniform dark line means done. For copper plates a 45° point is the best all-rounder, 50–55° for hard brass and steel dies, 30° for soft lead. Stroke figure-eights with the handle braced in the shoulder hollow, face flat on the stone; one sharpening runs 2–3 hours, and any drag in the cut sends you back to the stones.