diff --git a/docs/plant-operation.html b/docs/plant-operation.html
index 7276992..0e51f19 100644
--- a/docs/plant-operation.html
+++ b/docs/plant-operation.html
@@ -299,6 +299,9 @@ const $=id=>document.getElementById(id);
 const COMPACT=matchMedia('(max-height:560px)');
 const L={pipes:$('lPipes'),mach:$('lMach'),tok:$('lTok'),top:$('lTop')};
 function el(tag,attrs,parent,text){const e=document.createElementNS(NS,tag);for(const k in attrs)e.setAttribute(k,attrs[k]);if(text!=null)e.textContent=text;(parent||L.mach).appendChild(e);return e;}
+// Machine header band: top corners rounded concentric with the box (rx 4, band inset 1, so radius 3).
+// A square band paints over the inside of the curved border at both top corners.
+const headD=(x,y,w)=>`M${x+1},${y+19}V${y+4}a3,3 0 0 1 3,-3H${x+w-4}a3,3 0 0 1 3,3V${y+19}Z`;
 const rnd=(a,b)=>a+Math.random()*(b-a);
 const jit=(v,a)=>v+(Math.random()-.5)*a;
 const pick=a=>a[Math.floor(Math.random()*a.length)];
@@ -639,7 +642,7 @@ el('text',{x:1368,y:24,class:'roomlbl'},L.mach,'Stamper prep · Sibert');
 
 function boxBase(m){const g=el('g',{class:'machine',id:'m_'+m.id});
   el('rect',{x:m.x,y:m.y,width:m.w,height:m.h,rx:4,class:'mbox'},g);
-  el('rect',{x:m.x+1,y:m.y+1,width:m.w-2,height:18,class:'mhead'},g);
+  el('path',{d:headD(m.x,m.y,m.w),class:'mhead'},g);
   el('text',{x:m.x+7,y:m.y+14,class:'mtitle'},g,m.t);
   m.lamp=el('circle',{cx:m.x+m.w-10,cy:m.y+10,r:4,class:'lamp'},g);
   if(m.s)el('text',{x:m.x+7,y:m.y+31,class:'msub'},g,m.s);
@@ -658,7 +661,7 @@ function drawSilo(m){const g=el('g',{class:'machine',id:'m_'+m.id});const {x,y,w
   m.g=g;g.addEventListener('click',()=>select(m.id));}
 function drawPress(m){const g=el('g',{class:'machine',id:'m_'+m.id});const {x,y,w,h}=m;
   el('rect',{x,y,width:w,height:h,rx:4,class:'frame'},g);
-  el('rect',{x:x+1,y:y+1,width:w-2,height:18,class:'mhead'},g);
+  el('path',{d:headD(x,y,w),class:'mhead'},g);
   el('text',{x:x+7,y:y+14,class:'mtitle'},g,m.t);
   m.lamp=el('circle',{cx:x+w-10,cy:y+10,r:4,class:'lamp'},g);
   el('text',{x:x+7,y:y+31,class:'msub'},g,m.s);
@@ -675,7 +678,7 @@ function drawPress(m){const g=el('g',{class:'machine',id:'m_'+m.id});const {x,y,
   m.g=g;g.addEventListener('click',()=>select(m.id));}
 function drawVex(m){const g=el('g',{class:'machine',id:'m_'+m.id});const {x,y,w,h}=m;
   el('rect',{x,y,width:w,height:h,rx:4,class:'mbox'},g);
-  el('rect',{x:x+1,y:y+1,width:w-2,height:18,class:'mhead'},g);
+  el('path',{d:headD(x,y,w),class:'mhead'},g);
   el('text',{x:x+7,y:y+14,class:'mtitle'},g,'VEX 50 extruder');
   m.lamp=el('circle',{cx:x+w-10,cy:y+10,r:4,class:'lamp'},g);
   m.tagEls=[el('text',{x:x+7,y:y+31,class:'msub'},g,''),el('text',{x:x+7,y:y+43,class:'msub'},g,'')];