diff --git a/control.cpp b/control.cpp
index c1ad3e7d..9f0f06b9 100644
--- a/control.cpp
+++ b/control.cpp
@@ -338,8 +338,8 @@ bool handleTune(int sym, int uni) {
   else if(uni == 'z')
     bscale7 = bscale6 = 1, brot7 = brot6 = 0;
   else return false;
-  printf("s7 %lf r7 %lf s6 %lf r6 %lf\n", bscale7, brot7, bscale6, brot6);
   resetGeometry();
+  println(hlog, spaced(bscale7, brot7, bscale6, brot6));
   return true;
   }
 #endif
diff --git a/irregular.cpp b/irregular.cpp
index a0df1fa9..875ee0d8 100644
--- a/irregular.cpp
+++ b/irregular.cpp
@@ -898,7 +898,7 @@ void show_gridmaker() {
       int s = cellcount;
       if(density < 1) density = 1;
       cellcount = int(isize(currentmap->allcells()) * density + .5);
-      printf("density = %lf cellcount = %d\n", double(density), cellcount);
+      println(hlog, "density = ", fts(density), " cellcount = ", cellcount);
       if(cellcount > s) runlevel = 1;
       if(cellcount < s) runlevel = 0;
       };
@@ -910,7 +910,7 @@ void show_gridmaker() {
       "Tilings with low values are easier to generate, but tend to be more ugly."
       ));
     dialog::reaction = [] () {
-      printf("quality = %lf\n", double(density));
+      println(hlog, "quality = ", density);
       if(runlevel > 4) runlevel = 4;
       };
     });
diff --git a/polygons.cpp b/polygons.cpp
index 41570e78..a9b0bb38 100644
--- a/polygons.cpp
+++ b/polygons.cpp
@@ -1857,7 +1857,7 @@ void finishshape() {
       if(asign(y1, y2)) {
         ld x = xcross(x1, y1, x2, y2);
         if(abs(x) < 1e-3 && !(last->flags & POLY_ISSIDE)) {
-          if(s >= 2 && DIM == 2) printf("close call [%d], x = %lf\n", s, x);
+          if(s >= 2 && DIM == 2) println(hlog, "close call [", s, "], x = ", fts(x));
           last->flags |= POLY_BADCENTERIN;
           }
         if(x < 0) last->flags ^= POLY_CENTERIN;