diff --git a/bitmap/name_tag.scad b/bitmap/name_tag.scad
index 366dce0..4b392bb 100644
--- a/bitmap/name_tag.scad
+++ b/bitmap/name_tag.scad
@@ -9,13 +9,13 @@ use <bitmap.scad>
 
 /*
  chars = chars array
- char_count = number of characters (OpenSCAD has no string or length methods)
  block_size = letter size (block size 1 will result in 8mm per letter)
  height = the Z height of each letter in mm
  key_ring_hole = (boolean) Append a hole to a keyring, necklace etc. ?
 */
-module name_tag(chars = ["R", "E", "P", "R", "A", "P"], char_count = 6,
+module name_tag(chars = ["R", "E", "P", "R", "A", "P"],
     block_size = 2, height = 3, key_ring_hole = true) {
+  char_count = len(chars);
   union() {
     translate(v = [0,-block_size*8*char_count/2+block_size*8/2,3]) {
       8bit_str(chars, char_count, block_size, height);
diff --git a/bitmap/test_name_tag.scad b/bitmap/test_name_tag.scad
index a921491..a3bcf40 100644
--- a/bitmap/test_name_tag.scad
+++ b/bitmap/test_name_tag.scad
@@ -1,19 +1,19 @@
 include <../bitmap/name_tag.scad>;
 
 translate([0,0,0])
-name_tag(["n","a","m","e","_","t","a","g"], 8);
+name_tag("name_tag");
 
 translate([20,0,0]) // 0 + 16/2 + 16/2 + 4
-name_tag(["N","A","M","E","_","T","A","G"], 8);
+name_tag("NAME_TAG");
 
 translate([52,0,0]) // 20 + 16/2 + 40/2 + 4
-name_tag(chars=["n","a","m","e","_","t","a","g"], char_count=8, block_size=5);
+name_tag("name_tag", block_size=5);
 
 translate([96,0,0]) // 52 + 40/2 + 40/2 + 4
-name_tag(chars=["N","A","M","E","_","T","A","G"], char_count=8, block_size=5);
+name_tag("NAME_TAG", block_size=5);
 
 translate([130,0,0]) // 92 + 40/2 + 16/2 + 4
-name_tag(["n","a","m","e","_","t","a","g"], char_count=8, height=30);
+name_tag("name_tag", height=30);
 
 translate([150,0,0]) // 130 + 16/2 + 16/2 + 4
-name_tag(["N","A","M","E","_","T","A","G"], char_count=8, height=30);
+name_tag("NAME_TAG", height=30);