diff --git a/js/kiri-driver-fdm.js b/js/kiri-driver-fdm.js
index 0b2210bc..b7fecd5f 100644
--- a/js/kiri-driver-fdm.js
+++ b/js/kiri-driver-fdm.js
@@ -161,7 +161,7 @@ var gs_kiri_fdm = exports;
                 }, "infill");
             }
 
-            let polish = spro.layerPolishing;
+            let polish = spro.polishLayers;
             // experimental polishing
             if (polish) {
                 let polish_layer = Math.floor(polish);
@@ -198,7 +198,13 @@ var gs_kiri_fdm = exports;
                     // console.log({polish_update});
                 });
                 // apply polishing finishes to layers
-                forSlices(1.0, 1.0, slice => {
+                forSlices(1.0, 1.0, (slice) => {
+                    if (polish_layer >= 2) {
+                        let sai = (slice.index - polish_layer);
+                        if (sai % (polish_layer-1) !== 0) {
+                            return;
+                        }
+                    }
                     if (slice.index >= polish_layer) {
                         let sd = slice;
                         for (let i=0; i<polish_layer; i++) {
@@ -228,10 +234,12 @@ var gs_kiri_fdm = exports;
                                     return;
                                 }
                                 // order points lowest to highest
+                                let swap = false;
                                 if (p1.z > p2.z) {
                                     let t = p2;
                                     p2 = p1;
                                     p1 = t;
+                                    swap = true;
                                 }
                                 let trimlo = false;
                                 let trimhi = false;
@@ -250,8 +258,8 @@ var gs_kiri_fdm = exports;
                                     p2 = BASE.newPoint(p2.x,p2.z,p2.y);
                                 }
                                 let slope = BASE.newSlope(p1, p2);
-                                let angle = Math.abs(slope.angle);
-                                if (angle > 40 && angle < 140) {
+                                let angle = slope.angle;
+                                if (angle > 80 && angle < 100) {
                                     return;
                                 }
                                 let len = p1.distTo2D(p2);
@@ -281,7 +289,8 @@ var gs_kiri_fdm = exports;
                                 if (!lastp) {
                                     poly.push(p1);
                                     poly.push(p2);
-                                } else if (p1.isEqual(lastp)) {
+                                } else if (p1.isMergable2D(lastp)) {
+                                // } else if (p1.isEqual(lastp)) {
                                     poly.push(p2);
                                     cont++;
                                 } else if (poly.length) {
@@ -296,17 +305,17 @@ var gs_kiri_fdm = exports;
                         });
                         pout.push(polys);
                         polys = [];
-
                         });
 
                         if (pout.length && slice.tops.length) {
                             slice.tops[0].polish = {
                                 x: pout[0]
                                     .map(a => BASE.newPolygon(a).setOpen())
-                                    .filter(p => p.perimeter() > sdev.nozzleSize),
+                                    // .filter(p => p.perimeter() > sdev.nozzleSize)
+                                    ,
                                 y: pout[1]
                                     .map(a => BASE.newPolygon(a).setOpen())
-                                    .filter(p => p.perimeter() > sdev.nozzleSize)
+                                    // .filter(p => p.perimeter() > sdev.nozzleSize)
                             };
                         }
                     }
@@ -812,7 +821,9 @@ var gs_kiri_fdm = exports;
                     moveTo({x:x, y:y, e:emitMM}, speedMMM);
                     emitted += emitMM;
                 } else {
-                    moveTo({x:x, y:y, z:z}, seekMMM);
+                    // when making z moves (like polishing) allow slowdown vs fast seek
+                    let moveSpeed = (lastp && lastp.z !== z) ? speedMMM : seekMMM;
+                    moveTo({x:x, y:y, z:z}, moveSpeed);
                 }
 
                 // retract filament
diff --git a/js/kiri-print.js b/js/kiri-print.js
index 6cc62ee9..55fbe5ab 100644
--- a/js/kiri-print.js
+++ b/js/kiri-print.js
@@ -597,7 +597,7 @@ var gs_kiri_print = exports;
         /**
          * @param {Polygon[]} polys
          */
-        function outputSparse(polys, extrude) {
+        function outputSparse(polys, extrude, speed) {
             if (!polys) return;
             var proxy = polys.map(function(poly) {
                 return {poly: poly, first: poly.first(), last: poly.last()};
@@ -611,7 +611,7 @@ var gs_kiri_print = exports;
                     if (i === 0 && lp && lp.distTo2D(p) > retractDist && intersectsTop(lp,p)) {
                         retract();
                     }
-                    addOutput(preout, p, i === 0 ? 0 : extrude, printSpeed);
+                    addOutput(preout, p, i === 0 ? 0 : extrude, speed || printSpeed);
                     lp = p;
                 });
             });
@@ -806,10 +806,10 @@ var gs_kiri_print = exports;
         if (slice.tops.length && slice.tops[0].polish) {
             let {x,y} = slice.tops[0].polish;
             if (x) {
-                outputSparse(x, 0);
+                outputSparse(x, 0, process.polishSpeed);
             }
             if (y) {
-                outputSparse(y, 0);
+                outputSparse(y, 0, process.polishSpeed);
             }
         }
 
diff --git a/js/kiri.js b/js/kiri.js
index ee327ae5..dfe284d9 100644
--- a/js/kiri.js
+++ b/js/kiri.js
@@ -103,7 +103,8 @@ self.kiri.license = exports.LICENSE;
                     // detectThinWalls: 1,
                     antiBacklash: 1,
                     zHopDistance: 1,
-                    layerPolishing: 1,
+                    polishLayers: 1,
+                    polishSpeed: 1,
                     outputLayerRetract: 1,
                     gcodeNozzle: 1,
                     gcodePauseLayers: 1,
@@ -339,7 +340,8 @@ self.kiri.license = exports.LICENSE;
                 detectThinWalls: false,
                 antiBacklash: 1,
                 zHopDistance: 0.2,
-                layerPolishing: 0,
+                polishLayers: 0,
+                polishSpeed: 40,
                 outputLayerRetract: false,
                 gcodeNozzle: 0,
                 gcodePauseLayers: "",
@@ -2898,7 +2900,8 @@ self.kiri.license = exports.LICENSE;
             zHopDistance: UC.newInput("z hop dist", {title: "amount to raise z\non retraction moves\nin millimeters\n0 to disable", bound:UC.bound(0,3.0), convert:UC.toFloat, modes:FDM, expert: true}),
             antiBacklash: UC.newInput("anti-backlash", {title: "use micro-movements to cancel\nbacklash during fills\nin millimeters", bound:UC.bound(0,3), convert:UC.toInt, modes:FDM, expert: true}),
             // detectThinWalls: UC.newBoolean("thin wall fill", onBooleanClick, {title: "detect and fill thin openings\nbetween shells walls", modes:FDM, expert: true})
-            layerPolishing: LOCAL ? UC.newInput("layer polish", {title:"polish up to specified\n# of layers at a time", bound:UC.bound(0,10), convert:UC.toFloat, modes:FDM, expert: true}) : null,
+            polishLayers: LOCAL ? UC.newInput("polish layers", {title:"polish up to specified\n# of layers at a time", bound:UC.bound(0,10), convert:UC.toFloat, modes:FDM, expert: true}) : null,
+            polishSpeed: LOCAL ? UC.newInput("polish speed", {title:"polishing speed\nin millimeters / minute", bound:UC.bound(10,2000), convert:UC.toInt, modes:FDM, expert: true}) : null,
             outputLayerRetract: UC.newBoolean("layer retract", onBooleanClick, {title:"force filament retraction\nbetween layers", modes:FDM, expert: true}),
 
             gcodeVars: UC.newGroup("gcode", null, {modes:FDM, expert: true}),