diff --git a/Code/thermal_printer/config.h b/Code/thermal_printer/config.h
index 7aaf19a..d08ee2f 100644
--- a/Code/thermal_printer/config.h
+++ b/Code/thermal_printer/config.h
@@ -167,12 +167,13 @@
 #define PRINT_STATE 0
 #define ESC_STATE 1
 #define GET_IMAGE 2
+#define GET_GRAY_IMAGE 3
 
 #define ALIGN_LEFT 0
 #define ALIGN_CENTER 1
 #define ALIGN_RIGHT 2
 
-#define IMAGE_MAX 9224
+#define IMAGE_MAX (9224*64)
 
 #define BITS8 8
 
diff --git a/Code/thermal_printer/devterm_thermal_printer.c b/Code/thermal_printer/devterm_thermal_printer.c
index 0a0909e..867d8f4 100644
--- a/Code/thermal_printer/devterm_thermal_printer.c
+++ b/Code/thermal_printer/devterm_thermal_printer.c
@@ -683,6 +683,23 @@ void parse_cmd(CONFIG *cfg, uint8_t *cmd, uint8_t cmdidx) {
       cmd_idx = 0;
       ser_cache.idx = 0;
     }
+    // GS v 1 p wL wH hL hH d1…dk
+    if (cmd[0] == ASCII_GS && cmd[1] == 118 && cmd[2] == 49) {
+      uint16_t width = cmd[4] + cmd[5] * 256;
+      uint16_t height = cmd[6] + cmd[7] * 256;
+      uint16_t k;
+      k = width * height;
+      if (k <= IMAGE_MAX) {
+        cfg->state = GET_GRAY_IMAGE;
+        cfg->img->num = k;
+        cfg->img->idx = 0;
+        cfg->img->width = width;
+        cfg->img->need_print = 1;
+      }
+      // do not reset_cmd()
+      cmd_idx = 0;
+      ser_cache.idx = 0;
+    }
   }
 }
 
@@ -700,6 +717,16 @@ void parse_serial_stream(CONFIG *cfg, uint8_t input_ch) {
       reset_cmd();
       cfg->state = PRINT_STATE;
     }
+  } else if (cfg->state == GET_GRAY_IMAGE) {
+    cfg->img->cache[cfg->img->idx] = input_ch;
+    cfg->img->idx++;
+    if (cfg->img->idx >= cfg->img->num) { // image full
+      if (cfg->img->need_print == 1) {
+        print_gray_image8(cfg);
+      }
+      reset_cmd();
+      cfg->state = PRINT_STATE;
+    }
   } else if (cfg->state == ESC_STATE) {
     cmd[cmd_idx] = input_ch;
     cmd_idx++;
diff --git a/Code/thermal_printer/printer.c b/Code/thermal_printer/printer.c
index 7c09058..2ccf646 100644
--- a/Code/thermal_printer/printer.c
+++ b/Code/thermal_printer/printer.c
@@ -340,7 +340,7 @@ void print_dots_8bit(CONFIG *cfg, uint8_t *Array, uint8_t characters,
 
   while (y < STB_NUMBER) {
 
-    while (i < 10) {
+    while (i < cfg->density) {
 
       digitalWrite(STBx[y], HIGH);
       delayus(HEAT_TIME + cfg->density * 46);
@@ -837,6 +837,68 @@ uint8_t print_image8(CONFIG *cfg) {
   return rv;
 }
 
+uint8_t print_gray_image8(CONFIG *cfg) {
+
+  uint16_t height;
+  uint16_t x, y, addr;
+
+  uint8_t rv;
+  uint8_t LinePixels[MAXPIXELS];
+
+  uint8_t maxchars = PRINTER_BITS / 8;
+  height = cfg->img->num / cfg->img->width;
+  y = 0;
+  addr = 0;
+  // gray print uses 4 colors with following convention
+  // 3N+0th line has cfg->density/4
+  // 3N+1th line has cfg->density/2
+  // 3N+2th line has cfg->density
+  // white pixels should be unset in all 3 lines
+  uint8_t density = cfg->density;
+  uint8_t feed_pitch = cfg->feed_pitch;
+  rv = IsPaper();
+  ENABLE_VH;
+  while (y < height) {
+    x = 0;
+    while (x < cfg->img->width) {
+      addr = x + y * cfg->img->width;
+
+      if (cfg->img->revert_bits > 0) // LSB
+        LinePixels[x] = invert_bit(cfg->img->cache[addr]);
+      else
+        LinePixels[x] = cfg->img->cache[addr];
+
+      x++;
+    }
+    rv = IsPaper();
+    if (rv == IS_PAPER) {
+      if (y % 3 == 0) {
+	cfg->density = density / 4;
+	cfg->feed_pitch = 0;
+      }
+      if (y % 3 == 1) {
+	cfg->density = density / 2;
+	cfg->feed_pitch = 0;
+      }
+      if (y % 3 == 2) {
+	cfg->density = density;
+	cfg->feed_pitch = feed_pitch;
+      }
+      print_dots_8bit_split(cfg, LinePixels, x);
+      delayus(HEAT_TIME*2);
+    }
+    y++;
+  }
+  cfg->img->need_print = 0;
+
+  cfg->img->num = 0;
+  cfg->img->idx = 0;
+  cfg->img->width = 0;
+  DISABLE_VH;
+
+  return rv;
+}
+
 void print_cut_line(CONFIG *cfg) {
   uint8_t bs, i;
 
diff --git a/Code/thermal_printer/printer.h b/Code/thermal_printer/printer.h
index 7cc9344..3d3bae8 100644
--- a/Code/thermal_printer/printer.h
+++ b/Code/thermal_printer/printer.h
@@ -37,6 +37,7 @@ uint8_t print_lines8(CONFIG *,int,int);
 uint8_t invert_bit(uint8_t a);
 
 uint8_t print_image8(CONFIG *);
+uint8_t print_gray_image8(CONFIG *);
 void print_cut_line(CONFIG *);
 
 void printer_set_font_mode(CONFIG *cfg, int);