diff --git a/index.html b/index.html
index cf6eb2ca..fc388af6 100644
--- a/index.html
+++ b/index.html
@@ -603,6 +603,7 @@
               id="toggleBorders"
               data-tip="State borders: click to toggle, drag to raise or lower the layer. Ctrl + click to edit layer style"
               data-shortcut="D"
+              class="buttonoff"
               onclick="toggleBorders(event)"
             >
               Bor<u>d</u>ers
@@ -8030,7 +8031,8 @@
     <script src="modules/biomes.js?v=1.99.00"></script>
     <script src="modules/names-generator.js?v=1.87.14"></script>
     <script src="modules/cultures-generator.js?v=1.99.05"></script>
-    <script src="modules/renderers/state-labels.js?v=1.96.04"></script>
+    <script src="modules/renderers/draw-state-labels.js?v=1.103.00"></script>
+    <script src="modules/renderers/draw-borders.js?v=1.103.00"></script>
     <script src="modules/burgs-and-states.js?v=1.103.00"></script>
     <script src="modules/provinces-generator.js?v=1.103.00"></script>
     <script src="modules/routes-generator.js?v=1.99.04"></script>
diff --git a/main.js b/main.js
index dae6925a..8120e591 100644
--- a/main.js
+++ b/main.js
@@ -654,7 +654,6 @@ async function generate(options) {
     Provinces.getPoles();
     BurgsAndStates.defineBurgFeatures();
 
-    drawBorders();
     drawStateLabels();
 
     Rivers.specify();
diff --git a/modules/dynamic/auto-update.js b/modules/dynamic/auto-update.js
index 12ac1e5e..f7d78376 100644
--- a/modules/dynamic/auto-update.js
+++ b/modules/dynamic/auto-update.js
@@ -53,7 +53,6 @@ export function resolveVersionConflicts(mapVersion) {
     BurgsAndStates.defineStateForms();
     Provinces.generate();
     Provinces.getPoles();
-    drawBorders();
     if (!layerIsOn("toggleBorders")) $("#borders").fadeOut();
     if (!layerIsOn("toggleStates")) regions.attr("display", "none").selectAll("path").remove();
 
diff --git a/modules/dynamic/editors/states-editor.js b/modules/dynamic/editors/states-editor.js
index 3067d1b8..dbca9fff 100644
--- a/modules/dynamic/editors/states-editor.js
+++ b/modules/dynamic/editors/states-editor.js
@@ -643,13 +643,10 @@ function stateRemove(stateId) {
 
   debug.selectAll(".highlight").remove();
 
-  if (!layerIsOn("toggleStates")) toggleStates();
-  else drawStates();
-
-  if (!layerIsOn("toggleBorders")) toggleBorders();
-  else drawBorders();
-
+  if (layerIsOn("toggleStates")) drawStates();
+  if (layerIsOn("toggleBorders")) drawBorders();
   if (layerIsOn("toggleProvinces")) drawProvinces();
+
   refreshStatesEditor();
 }
 
@@ -844,13 +841,13 @@ function recalculateStates(must) {
   BurgsAndStates.expandStates();
   Provinces.generate();
   Provinces.getPoles();
-  if (!layerIsOn("toggleStates")) toggleStates();
-  else drawStates();
-  if (!layerIsOn("toggleBorders")) toggleBorders();
-  else drawBorders();
-  if (layerIsOn("toggleProvinces")) drawProvinces();
   BurgsAndStates.getPoles();
+
+  if (layerIsOn("toggleStates")) drawStates();
+  if (layerIsOn("toggleBorders")) drawBorders();
+  if (layerIsOn("toggleProvinces")) drawProvinces();
   if (adjustLabels.checked) drawStateLabels();
+
   refreshStatesEditor();
 }
 
diff --git a/modules/renderers/draw-borders.js b/modules/renderers/draw-borders.js
new file mode 100644
index 00000000..f0f3006e
--- /dev/null
+++ b/modules/renderers/draw-borders.js
@@ -0,0 +1,120 @@
+"use strict";
+
+function drawBorders() {
+  TIME && console.time("drawBorders");
+  const {cells, vertices} = pack;
+
+  const statePath = [];
+  const provincePath = [];
+  const checked = {};
+
+  const isLand = cellId => cells.h[cellId] >= 20;
+
+  for (let cellId = 0; cellId < cells.i.length; cellId++) {
+    if (!cells.state[cellId]) continue;
+    const provinceId = cells.province[cellId];
+    const stateId = cells.state[cellId];
+
+    // bordering cell of another province
+    if (provinceId) {
+      const provToCell = cells.c[cellId].find(neibId => {
+        const neibProvinceId = cells.province[neibId];
+        return (
+          neibProvinceId &&
+          provinceId > neibProvinceId &&
+          !checked[`prov-${provinceId}-${neibProvinceId}-${cellId}`] &&
+          cells.state[neibId] === stateId
+        );
+      });
+
+      if (provToCell !== undefined) {
+        const addToChecked = cellId => (checked[`prov-${provinceId}-${cells.province[provToCell]}-${cellId}`] = true);
+        const border = getBorder({type: "province", fromCell: cellId, toCell: provToCell, addToChecked});
+
+        if (border) {
+          provincePath.push(border);
+          cellId--; // check the same cell again
+          continue;
+        }
+      }
+    }
+
+    // if cell is on state border
+    const stateToCell = cells.c[cellId].find(neibId => {
+      const neibStateId = cells.state[neibId];
+      return isLand(neibId) && stateId > neibStateId && !checked[`state-${stateId}-${neibStateId}-${cellId}`];
+    });
+
+    if (stateToCell !== undefined) {
+      const addToChecked = cellId => (checked[`state-${stateId}-${cells.state[stateToCell]}-${cellId}`] = true);
+      const border = getBorder({type: "state", fromCell: cellId, toCell: stateToCell, addToChecked});
+
+      if (border) {
+        statePath.push(border);
+        cellId--; // check the same cell again
+        continue;
+      }
+    }
+  }
+
+  svg.select("#borders").selectAll("path").remove();
+  svg.select("#stateBorders").append("path").attr("d", statePath.join(" "));
+  svg.select("#provinceBorders").append("path").attr("d", provincePath.join(" "));
+
+  function getBorder({type, fromCell, toCell, addToChecked}) {
+    const getType = cellId => cells[type][cellId];
+    const isTypeFrom = cellId => cellId < cells.i.length && getType(cellId) === getType(fromCell);
+    const isTypeTo = cellId => cellId < cells.i.length && getType(cellId) === getType(toCell);
+
+    addToChecked(fromCell);
+    const startingVertex = cells.v[fromCell].find(v => vertices.c[v].some(i => isLand(i) && isTypeTo(i)));
+    if (startingVertex === undefined) return null;
+
+    const checkVertex = vertex =>
+      vertices.c[vertex].some(isTypeFrom) && vertices.c[vertex].some(c => isLand(c) && isTypeTo(c));
+    const chain = getVerticesLine({vertices, startingVertex, checkCell: isTypeFrom, checkVertex, addToChecked});
+    if (chain.length > 1) return "M" + chain.map(cellId => vertices.p[cellId]).join(" ");
+
+    return null;
+  }
+
+  // connect vertices to chain to form a border
+  function getVerticesLine({vertices, startingVertex, checkCell, checkVertex, addToChecked}) {
+    let chain = []; // vertices chain to form a path
+    let next = startingVertex;
+    const MAX_ITERATIONS = vertices.c.length;
+
+    for (let run = 0; run < 2; run++) {
+      // first run: from any vertex to a border edge
+      // second run: from found border edge to another edge
+      chain = [];
+
+      for (let i = 0; i < MAX_ITERATIONS; i++) {
+        const previous = chain.at(-1);
+        const current = next;
+        chain.push(current);
+
+        const neibCells = vertices.c[current];
+        neibCells.map(addToChecked);
+
+        const [c1, c2, c3] = neibCells.map(checkCell);
+        const [v1, v2, v3] = vertices.v[current].map(checkVertex);
+        const [vertex1, vertex2, vertex3] = vertices.v[current];
+
+        if (v1 && vertex1 !== previous && c1 !== c2) next = vertex1;
+        else if (v2 && vertex2 !== previous && c2 !== c3) next = vertex2;
+        else if (v3 && vertex3 !== previous && c1 !== c3) next = vertex3;
+
+        if (next === current || next === startingVertex) {
+          if (next === startingVertex) chain.push(startingVertex);
+          startingVertex = next;
+          break;
+        }
+      }
+    }
+
+    return chain;
+  }
+
+  TIME && console.timeEnd("drawBorders");
+}
diff --git a/modules/renderers/state-labels.js b/modules/renderers/draw-state-labels.js
similarity index 99%
rename from modules/renderers/state-labels.js
rename to modules/renderers/draw-state-labels.js
index b0cf3001..15bb7ea5 100644
--- a/modules/renderers/state-labels.js
+++ b/modules/renderers/draw-state-labels.js
@@ -2,7 +2,7 @@
 
 // list - an optional array of stateIds to regenerate
 function drawStateLabels(list) {
-  console.time("drawStateLabels");
+  TIME && console.time("drawStateLabels");
 
   // temporary make the labels visible
   const layerDisplay = labels.style("display");
@@ -289,5 +289,5 @@ function drawStateLabels(list) {
     return false;
   }
 
-  console.timeEnd("drawStateLabels");
+  TIME && console.timeEnd("drawStateLabels");
 }
diff --git a/modules/submap.js b/modules/submap.js
index c4028d6e..5389bcaa 100644
--- a/modules/submap.js
+++ b/modules/submap.js
@@ -273,7 +273,6 @@ window.Submap = (function () {
     stage("Regenerating routes network.");
     regenerateRoutes();
 
-    drawBorders();
     drawStateLabels();
 
     Rivers.specify();
diff --git a/modules/ui/heightmap-editor.js b/modules/ui/heightmap-editor.js
index 3f684bdc..fa1427f3 100644
--- a/modules/ui/heightmap-editor.js
+++ b/modules/ui/heightmap-editor.js
@@ -253,7 +253,6 @@ function editHeightmap(options) {
     Provinces.getPoles();
     BurgsAndStates.defineBurgFeatures();
 
-    drawBorders();
     drawStateLabels();
 
     Rivers.specify();
@@ -440,7 +439,6 @@ function editHeightmap(options) {
     }
 
     drawStateLabels();
-    drawBorders();
 
     if (erosionAllowed) {
       Rivers.specify();
diff --git a/modules/ui/layers.js b/modules/ui/layers.js
index f8a9542b..acb8736a 100644
--- a/modules/ui/layers.js
+++ b/modules/ui/layers.js
@@ -182,10 +182,10 @@ function restoreLayers() {
   if (layerIsOn("toggleEmblems")) drawEmblems();
   if (layerIsOn("toggleMarkers")) drawMarkers();
   if (layerIsOn("toggleZones")) drawZones();
+  if (layerIsOn("toggleBorders")) drawBorders();
+  if (layerIsOn("toggleStates")) drawStates();
 
   // some layers are rendered each time, remove them if they are not on
-  if (!layerIsOn("toggleBorders")) borders.selectAll("path").remove();
-  if (!layerIsOn("toggleStates")) regions.selectAll("path").remove();
   if (!layerIsOn("toggleRivers")) rivers.selectAll("*").remove();
 }
 
@@ -871,114 +871,6 @@ function toggleBorders(event) {
   }
 }
 
-// draw state and province borders
-function drawBorders() {
-  TIME && console.time("drawBorders");
-  borders.selectAll("path").remove();
-
-  const {cells, vertices} = pack;
-  const n = cells.i.length;
-
-  const sPath = [];
-  const pPath = [];
-
-  const sUsed = new Array(pack.states.length).fill("").map(_ => []);
-  const pUsed = new Array(pack.provinces.length).fill("").map(_ => []);
-
-  for (let i = 0; i < cells.i.length; i++) {
-    if (!cells.state[i]) continue;
-    const p = cells.province[i];
-    const s = cells.state[i];
-
-    // if cell is on province border
-    const provToCell = cells.c[i].find(
-      n => cells.state[n] === s && p > cells.province[n] && pUsed[p][n] !== cells.province[n]
-    );
-
-    if (provToCell) {
-      const provTo = cells.province[provToCell];
-      pUsed[p][provToCell] = provTo;
-      const vertex = cells.v[i].find(v => vertices.c[v].some(i => cells.province[i] === provTo));
-      const chain = connectVertices(vertex, p, cells.province, provTo, pUsed);
-
-      if (chain.length > 1) {
-        pPath.push("M" + chain.map(c => vertices.p[c]).join(" "));
-        i--;
-        continue;
-      }
-    }
-
-    // if cell is on state border
-    const stateToCell = cells.c[i].find(n => cells.h[n] >= 20 && s > cells.state[n] && sUsed[s][n] !== cells.state[n]);
-    if (stateToCell !== undefined) {
-      const stateTo = cells.state[stateToCell];
-      sUsed[s][stateToCell] = stateTo;
-      const vertex = cells.v[i].find(v => vertices.c[v].some(i => cells.h[i] >= 20 && cells.state[i] === stateTo));
-      const chain = connectVertices(vertex, s, cells.state, stateTo, sUsed);
-
-      if (chain.length > 1) {
-        sPath.push("M" + chain.map(c => vertices.p[c]).join(" "));
-        i--;
-        continue;
-      }
-    }
-  }
-
-  stateBorders.append("path").attr("d", sPath.join(" "));
-  provinceBorders.append("path").attr("d", pPath.join(" "));
-
-  // connect vertices to chain
-  function connectVertices(current, f, array, t, used) {
-    let chain = [];
-    const checkCell = c => c >= n || array[c] !== f;
-    const checkVertex = v =>
-      vertices.c[v].some(c => array[c] === f) && vertices.c[v].some(c => array[c] === t && cells.h[c] >= 20);
-
-    // find starting vertex
-    for (let i = 0; i < 1000; i++) {
-      if (i === 999) ERROR && console.error("Find starting vertex: limit is reached", current, f, t);
-      const p = chain[chain.length - 2] || -1; // previous vertex
-      const v = vertices.v[current],
-        c = vertices.c[current];
-
-      const v0 = checkCell(c[0]) !== checkCell(c[1]) && checkVertex(v[0]);
-      const v1 = checkCell(c[1]) !== checkCell(c[2]) && checkVertex(v[1]);
-      const v2 = checkCell(c[0]) !== checkCell(c[2]) && checkVertex(v[2]);
-      if (v0 + v1 + v2 === 1) break;
-      current = v0 && p !== v[0] ? v[0] : v1 && p !== v[1] ? v[1] : v[2];
-
-      if (current === chain[0]) break;
-      if (current === p) return [];
-      chain.push(current);
-    }
-
-    chain = [current]; // vertices chain to form a path
-    // find path
-    for (let i = 0; i < 1000; i++) {
-      if (i === 999) ERROR && console.error("Find path: limit is reached", current, f, t);
-      const p = chain[chain.length - 2] || -1; // previous vertex
-      const v = vertices.v[current],
-        c = vertices.c[current];
-      c.filter(c => array[c] === t).forEach(c => (used[f][c] = t));
-
-      const v0 = checkCell(c[0]) !== checkCell(c[1]) && checkVertex(v[0]);
-      const v1 = checkCell(c[1]) !== checkCell(c[2]) && checkVertex(v[1]);
-      const v2 = checkCell(c[0]) !== checkCell(c[2]) && checkVertex(v[2]);
-      current = v0 && p !== v[0] ? v[0] : v1 && p !== v[1] ? v[1] : v[2];
-
-      if (current === p) break;
-      if (current === chain[chain.length - 1]) break;
-      if (chain.length > 1 && v0 + v1 + v2 < 2) break;
-      chain.push(current);
-      if (current === chain[0]) break;
-    }
-
-    return chain;
-  }
-
-  TIME && console.timeEnd("drawBorders");
-}
-
 function toggleProvinces(event) {
   if (!layerIsOn("toggleProvinces")) {
     turnButtonOn("toggleProvinces");
diff --git a/modules/ui/provinces-editor.js b/modules/ui/provinces-editor.js
index 2846a054..dba4a741 100644
--- a/modules/ui/provinces-editor.js
+++ b/modules/ui/provinces-editor.js
@@ -490,8 +490,7 @@ function editProvinces() {
           const g = provs.select("#provincesBody");
           g.select("#province" + p).remove();
           g.select("#province-gap" + p).remove();
-          if (!layerIsOn("toggleBorders")) toggleBorders();
-          else drawBorders();
+          if (layerIsOn("toggleBorders")) drawBorders();
           refreshProvincesEditor();
           $(this).dialog("close");
         },
@@ -950,12 +949,9 @@ function editProvinces() {
         pack.cells.province[i] = +this.dataset.province;
       });
 
-    if (!layerIsOn("toggleBorders")) toggleBorders();
-    else drawBorders();
-
     Provinces.getPoles();
-    if (!layerIsOn("toggleProvinces")) toggleProvinces();
-    else drawProvinces();
+    if (layerIsOn("toggleBorders")) drawBorders();
+    if (layerIsOn("toggleProvinces")) drawProvinces();
 
     exitProvincesManualAssignment();
     refreshProvincesEditor();
@@ -1047,10 +1043,9 @@ function editProvinces() {
       cells.province[c] = province;
     });
 
-    if (!layerIsOn("toggleBorders")) toggleBorders();
-    else drawBorders();
-    if (!layerIsOn("toggleProvinces")) toggleProvinces();
-    else drawProvinces();
+    if (layerIsOn("toggleBorders")) drawBorders();
+    if (layerIsOn("toggleProvinces")) drawProvinces();
+
     collectStatistics();
     byId("provincesFilterState").value = state;
     provincesEditorAddLines();
@@ -1123,8 +1118,7 @@ function editProvinces() {
           pack.states.forEach(s => (s.provinces = []));
 
           unfog();
-          if (!layerIsOn("toggleBorders")) toggleBorders();
-          else drawBorders();
+          if (layerIsOn("toggleBorders")) drawBorders();
           provs.select("#provincesBody").remove();
           turnButtonOff("toggleProvinces");
 
diff --git a/modules/ui/tools.js b/modules/ui/tools.js
index aa3b831a..33bff1aa 100644
--- a/modules/ui/tools.js
+++ b/modules/ui/tools.js
@@ -336,7 +336,8 @@ function regenerateProvinces() {
 
   Provinces.generate(true, true);
   Provinces.getPoles();
-  drawBorders();
+
+  if (layerIsOn("toggleBorders")) drawBorders();
   if (layerIsOn("toggleProvinces")) drawProvinces();
 
   // remove emblems