diff --git a/D03_PlanAnalysis/D03_PlanAnalysis_UI_Layers.ts b/D03_PlanAnalysis/D03_PlanAnalysis_UI_Layers.ts
index 8bc357afe..0ee401c75 100644
--- a/D03_PlanAnalysis/D03_PlanAnalysis_UI_Layers.ts
+++ b/D03_PlanAnalysis/D03_PlanAnalysis_UI_Layers.ts
@@ -229,6 +229,7 @@ export function createPlanLayers(opts: {
     const got = data.slope;
     if (!got) return;
     const turn = ++slopeTurn;
+    got.paintMs = -1; // 칠하는 중(검증 창구)
     const started = performance.now();
     const painted = await paintSlope(got.values, got.bands);
     if (turn !== slopeTurn || data.slope !== got) return URL.revokeObjectURL(painted.url);