diff --git a/src/kiri/conf.js b/src/kiri/conf.js
index df47ff6f..a5790c9f 100644
--- a/src/kiri/conf.js
+++ b/src/kiri/conf.js
@@ -275,6 +275,7 @@
                     processName: "default",
                     sliceHeight: 0.25,
                     sliceShells: 3,
+                    sliceShellOrder: "in-out",
                     sliceFillAngle: 45,
                     sliceFillOverlap: 0.3,
                     sliceFillSparse: 0.5,
diff --git a/src/kiri/init.js b/src/kiri/init.js
index 0fdcaaec..eac86bc7 100644
--- a/src/kiri/init.js
+++ b/src/kiri/init.js
@@ -1418,13 +1418,14 @@
             process:             UC.newGroup(LANG.sl_menu, $('settings'), {modes:FDM_LASER}),
             sliceHeight:         UC.newInput(LANG.sl_lahi_s, {title:LANG.sl_lahi_l, convert:UC.toFloat, modes:FDM}),
             sliceMinHeight:      UC.newInput(LANG.ad_minl_s, {title:LANG.ad_minl_l, bound:UC.bound(0,3.0), convert:UC.toFloat, modes:FDM, expert:true, show: () => UI.sliceAdaptive.checked}),
+            fdmSep:              UC.newBlank({class:"pop-sep", modes:FDM}),
             sliceShells:         UC.newInput(LANG.sl_shel_s, {title:LANG.sl_shel_l, convert:UC.toInt, modes:FDM}),
             sliceTopLayers:      UC.newInput(LANG.sl_ltop_s, {title:LANG.sl_ltop_l, convert:UC.toInt, modes:FDM}),
             sliceSolidLayers:    UC.newInput(LANG.sl_lsld_s, {title:LANG.sl_lsld_l, convert:UC.toInt, modes:FDM}),
             sliceBottomLayers:   UC.newInput(LANG.sl_lbot_s, {title:LANG.sl_lbot_l, convert:UC.toInt, modes:FDM}),
             fdmSep:              UC.newBlank({class:"pop-sep", modes:FDM}),
-            detectThinWalls:     UC.newBoolean(LANG.ad_thin_s, onBooleanClick, {title: LANG.ad_thin_l, modes:FDM, expert:true}),
             sliceAdaptive:       UC.newBoolean(LANG.ad_adap_s, onBooleanClick, {title: LANG.ad_adap_l, modes:FDM, expert:true, trigger: true}),
+            detectThinWalls:     UC.newBoolean(LANG.ad_thin_s, onBooleanClick, {title: LANG.ad_thin_l, modes:FDM, expert:true}),
 
             laserOffset:         UC.newInput(LANG.ls_offs_s, {title:LANG.ls_offs_l, convert:UC.toFloat, modes:LASER}),
             laserSliceHeight:    UC.newInput(LANG.ls_lahi_s, {title:LANG.ls_lahi_l, convert:UC.toFloat, modes:LASER, trigger: true}),
@@ -1433,12 +1434,14 @@
 
             fdmInfill:           UC.newGroup(LANG.fi_menu, $('settings'), {modes:FDM, marker:true}),
             sliceFillType:       UC.newSelect(LANG.fi_type, {modes:FDM}, "infill"),
+            fdmSep:              UC.newBlank({class:"pop-sep", modes:FDM}),
             sliceFillSparse:     UC.newInput(LANG.fi_pcnt_s, {title:LANG.fi_pcnt_l, convert:UC.toFloat, bound:UC.bound(0.0,1.0), modes:FDM}),
             sliceFillAngle:      UC.newInput(LANG.fi_angl_s, {title:LANG.fi_angl_l, convert:UC.toFloat, modes:FDM, expert:true}),
             sliceFillOverlap:    UC.newInput(LANG.fi_over_s, {title:LANG.fi_over_l, convert:UC.toFloat, bound:UC.bound(0.0,2.0), modes:FDM, expert:true}),
 
             firstLayer:          UC.newGroup(LANG.fl_menu, null, {modes:FDM}),
             firstSliceHeight:    UC.newInput(LANG.fl_lahi_s, {title:LANG.fl_lahi_l, convert:UC.toFloat, modes:FDM}),
+            fdmSep:              UC.newBlank({class:"pop-sep", modes:FDM}),
             firstLayerRate:      UC.newInput(LANG.fl_rate_s, {title:LANG.fl_rate_l, convert:UC.toFloat, modes:FDM}),
             firstLayerFillRate:  UC.newInput(LANG.fl_frat_s, {title:LANG.fl_frat_l, convert:UC.toFloat, modes:FDM}),
             firstLayerPrintMult: UC.newInput(LANG.fl_mult_s, {title:LANG.fl_mult_l, convert:UC.toFloat, modes:FDM, expert:true}),
@@ -1451,14 +1454,16 @@
 
             fdmSupport:          UC.newGroup(LANG.sp_menu, null, {modes:FDM, marker:true}),
             sliceSupportDensity: UC.newInput(LANG.sp_dens_s, {title:LANG.sp_dens_l, convert:UC.toFloat, bound:UC.bound(0.05,1.0), modes:FDM}),
+            fdmSep:              UC.newBlank({class:"pop-sep", modes:FDM}),
             sliceSupportSize:    UC.newInput(LANG.sp_size_s, {title:LANG.sp_size_l, bound:UC.bound(1.0,200.0), convert:UC.toFloat, modes:FDM}),
             sliceSupportOffset:  UC.newInput(LANG.sp_offs_s, {title:LANG.sp_offs_l, bound:UC.bound(0.0,200.0), convert:UC.toFloat, modes:FDM}),
             sliceSupportGap:     UC.newInput(LANG.sp_gaps_s, {title:LANG.sp_gaps_l, bound:UC.bound(0,5), convert:UC.toInt, modes:FDM, expert:true}),
+            fdmSep:              UC.newBlank({class:"pop-sep", modes:FDM}),
             sliceSupportSpan:    UC.newInput(LANG.sp_span_s, {title:LANG.sp_span_l, bound:UC.bound(0.0,200.0), convert:UC.toFloat, modes:FDM}),
             sliceSupportArea:    UC.newInput(LANG.sp_area_s, {title:LANG.sp_area_l, bound:UC.bound(0.0,200.0), convert:UC.toFloat, modes:FDM}),
             sliceSupportExtra:   UC.newInput(LANG.sp_xpnd_s, {title:LANG.sp_xpnd_l, bound:UC.bound(0.0,200.0), convert:UC.toFloat, modes:FDM, expert:true}),
-            sliceSupportNozzle:  UC.newSelect(LANG.sp_nozl_s, {title:LANG.sp_nozl_l, modes:FDM, expert:true}, "extruders"),
             fdmSep:              UC.newBlank({class:"pop-sep", modes:FDM}),
+            sliceSupportNozzle:  UC.newSelect(LANG.sp_nozl_s, {title:LANG.sp_nozl_l, modes:FDM, expert:true}, "extruders"),
             sliceSupportEnable:  UC.newBoolean(LANG.enable, onBooleanClick, {modes:FDM}),
 
             fdmRaft:            UC.newGroup(LANG.fr_menu, null, {modes:FDM, marker:true}),
@@ -1571,6 +1576,7 @@
             outputSparseMult:    UC.newInput(LANG.ou_spml_s, {title:LANG.ou_exml_l, convert:UC.toFloat, bound:UC.bound(0.0,2.0), modes:FDM}),
             fdmSep:              UC.newBlank({class:"pop-sep", modes:FDM}),
             outputFanLayer:      UC.newInput(LANG.ou_fanl_s, {title:LANG.ou_fanl_l, convert:UC.toInt, bound:UC.bound(0,100), modes:FDM, expert:true}),
+            sliceShellOrder:     UC.newSelect(LANG.sl_ordr_s, {title:LANG.sl_ordr_l, modes:FDM}, "shell"),
             camConventional:     UC.newBoolean(LANG.ou_conv_s, onBooleanClick, {title:LANG.ou_conv_l, modes:CAM}),
             camEaseDown:         UC.newBoolean(LANG.cr_ease_s, onBooleanClick, {title:LANG.cr_ease_l, modes:CAM}),
             camDepthFirst:       UC.newBoolean(LANG.ou_depf_s, onBooleanClick, {title:LANG.ou_depf_l, modes:CAM}),
diff --git a/src/kiri/main.js b/src/kiri/main.js
index f4c18eee..f042f6c9 100644
--- a/src/kiri/main.js
+++ b/src/kiri/main.js
@@ -128,6 +128,10 @@
     };
 
     const lists = {
+        shell: [
+            { name: "in-out" },
+            { name: "out-in" },
+        ],
         infill: [
             { name: "vase" },
             { name: "hex" },
diff --git a/src/kiri/print.js b/src/kiri/print.js
index 1bbd63b5..43779a3d 100644
--- a/src/kiri/print.js
+++ b/src/kiri/print.js
@@ -397,6 +397,7 @@
             retractDist = opt.retractOver || 2,
             fillMult = opt.mult || process.outputFillMult,
             shellMult = opt.mult || process.outputShellMult || (process.laserSliceHeight >= 0 ? 1 : 0),
+            shellOrder = {"out-in":-1,"in-out":1}[process.sliceShellOrder] || -1,
             sparseMult = process.outputSparseMult,
             coastDist = process.outputCoastDist || 0,
             finishSpeed = opt.speed || process.outputFinishrate,
@@ -703,21 +704,19 @@
                 // top object
                 let bounds = POLY.flatten(next.shellsAtDepth(0).clone(true));
 
-                let dir = -1; // 1 == inside out, -1 == outside-in
-
                 // output inner polygons
-                if (dir === 1)
+                if (shellOrder === 1)
                 outputTraces([].appendAll(next.innerShells() || []));
 
                 // sort perimeter polygon by length to go out-to-in or in-to-out
                 (next.shells || []).sort(function(a,b) {
-                    return a.perimeter() > b.perimeter() ? dir : -dir;
+                    return a.perimeter() > b.perimeter() ? shellOrder : -shellOrder;
                 }).forEach(function(poly, index) {
                     outputTraces(poly);
                 });
 
                 // output outer polygons
-                if (dir === -1)
+                if (shellOrder === -1)
                 outputTraces([].appendAll(next.innerShells() || []));
 
                 // output thin fill
diff --git a/web/kiri/lang/en.js b/web/kiri/lang/en.js
index 53fecffc..29443c3d 100644
--- a/web/kiri/lang/en.js
+++ b/web/kiri/lang/en.js
@@ -180,24 +180,28 @@ kiri.lang['en-us'] = {
     se_save:        "save",
 
     // FDM SLICING
-    sl_menu:        "slicing",
-    sl_lahi_s:      "layer height",
+    sl_menu:        "layers",
+    sl_lahi_s:      "height",
     sl_lahi_l:      "height of each slice\nlayer in millimeters",
-    ad_minl_s:      "layer min",
+    ad_minl_s:      "height min",
     ad_minl_l:      "adaptive min layer height\nin millimeters\nmust be non-zero",
-    sl_shel_s:      "shell count",
-    sl_shel_l:      "number of perimeter\nwalls to generate",
     sl_ltop_s:      "top layers",
     sl_ltop_l:      "number of solid layers\nto enforce at the\ntop of the print",
     sl_lsld_s:      "solid layers",
     sl_lsld_l:      "solid fill areas computed\nfrom layer deltas. see\nlayer pop menu",
     sl_lbot_s:      "base layers",
     sl_lbot_l:      "number of solid layers\nto enforce at the\nbottom of the print",
-    ad_thin_s:      "thin walls",
-    ad_thin_l:      "detect and fill gaps\nbetween shell walls",
     ad_adap_s:      "adaptive",
     ad_adap_l:      "use adaptive layer heights\nwith 'layer height' as max\nand 'layer min' as the min",
 
+    // FDM SHELLS
+    sl_shel_s:      "shell count",
+    sl_shel_l:      "number of perimeter\nwalls to generate",
+    sl_ordr_s:      "shell order",
+    sl_ordr_l:      "output shell order\ninside to outside\nor outside to inside\naffects surface quality",
+    ad_thin_s:      "thin walls",
+    ad_thin_l:      "detect and fill gaps\nbetween shell walls",
+
     // FDM FILL
     fi_menu:        "infill",
     fi_type:        "type",