diff --git a/pitfall/pitfall/minimal-measured-font.rkt b/pitfall/pitfall/minimal-measured-font.rkt
index 1b800ca4..091386cb 100644
--- a/pitfall/pitfall/minimal-measured-font.rkt
+++ b/pitfall/pitfall/minimal-measured-font.rkt
@@ -1,87 +1,94 @@
-#lang at-exp s-exp pitfall/render
+#lang at-exp br
+(require pitfall/render)
 
-;; catalog object
-(co-io 1 0 (co-catalog #:pages (co-io-ref 2 0)))
+(render-args
 
-;; pages
-(co-io 2 0 (co-pages #:kids (list (co-io-ref 3 0))
-                     #:count 1))
-;; page
-(co-io 3 0 (co-page #:parent (co-io-ref 2 0)
-                    #:mediabox '(0 0 400 400)
-                    #:resources (co-io-ref 4 0)
-                    #:contents (co-io-ref 5 0)
+ ;; catalog object
+ (co-io 1 0 (co-catalog #:pages (co-io-ref 2 0)))
+
+ ;; pages
+ (co-io 2 0 (co-pages #:kids (list (co-io-ref 3 0))
+                      #:count 1))
+ ;; page
+ (co-io 3 0 (co-page #:parent (co-io-ref 2 0)
+                     #:mediabox '(0 0 400 400)
+                     #:resources (co-io-ref 4 0)
+                     #:contents (co-io-ref 5 0)
                     
-                    ; the value of annots must be an array
-                    #:annots (co-array (list (co-io-ref 7 0)))
-                    ))
-#;#:annots (co-io-ref 7 0)
+                     ; the value of annots must be an array
+                     #:annots (co-array (list (co-io-ref 7 0)))
+                     ))
+ #;#:annots (co-io-ref 7 0)
 
-;; resources
-(co-io 4 0
-       (make-co-dict
-        'ProcSet (co-array '(PDF Text))
-        'Font (make-co-dict 'F1 (co-io-ref 6 0))))
+ ;; resources
+ (co-io 4 0
+        (make-co-dict
+         'ProcSet (co-array '(PDF Text))
+         'Font (make-co-dict 'F1 (co-io-ref 6 0))))
 
-;; contents
-(co-io 5 0
-       (make-co-stream
-        #"
+ ;; contents
+ (co-io 5 0
+        (make-co-stream
+         #"
 BT
 /F1 48 Tf
-
-(Hello) Tj
-
-(World) Tj
+(Hello World 1-1!) Tj
 ET
 "))
 
 
-;; font
-(co-io 6 0
-       (make-co-dict
-        'Type 'Font
-        'Subtype 'Type1
-        'Name 'F1
-        'BaseFont 'FiraSansOTMedium
-        'FontDescriptor (co-io-ref 9 0)
-        'FirstChar 0
-        'LastChar 1150
-        'Widths (co-array (for/list ([i (in-range (add1 1150))])
-                                    (define m (measure-char-idx "fira.otf" i))
-                                    (displayln m)
-                                    m))
-        'Encoding 'MacRomanEncoding))
+ ;; font
+ (let ([last-char 255])
+   (co-io 6 0
+          (make-co-dict
+           'Type 'Font
+           'Subtype 'Type1
+           'Name 'F1
+           'BaseFont 'Helvetica
+           'FontDescriptor (co-io-ref 9 0)
+           'FirstChar 0
+           'LastChar last-char
+           ;; widths can only hold 256 apparently?
+           'Widths (report (co-array
+                            (for/list ([i (in-range (add1 last-char))])
+                              ;; 29 is magic number: this is offset betwee
+                              ;; ascii value and character index
+                              ;; so A (ascii 65) lives at index 36
+                              (define ascii-index-offset 29)
+                              (if (<= ascii-index-offset i)
+                                  (measure-char-idx "fira.otf" (- i ascii-index-offset))
+                                  200))))
+           'Encoding 'MacRomanEncoding)))
 
-(co-io 7 0
-       (make-co-dict 'Type 'Annot
-                     'Subtype 'Link
-                     'Rect (co-array '(100 100 150 125))
-                     'A (co-io-ref 8 0)))
+ (co-io 7 0
+        (make-co-dict 'Type 'Annot
+                      'Subtype 'Link
+                      'Rect (co-array '(100 100 150 125))
+                      'A (co-io-ref 8 0)))
 
 
-(co-io 8 0
-       (make-co-dict 'Type 'Action
-                     'S 'URI
-                     'URI (co-string "http://practicaltypography.com")))
+ (co-io 8 0
+        (make-co-dict 'Type 'Action
+                      'S 'URI
+                      'URI (co-string "http://practicaltypography.com")))
 
-(co-io 9 0
-       (make-co-dict
-        'Type 'FontDescriptor
-        'FontName 'FiraSansOTLight
-        'FontFile3 (co-io-ref 10 0)
-        'Flags 4
-        'FontBBox (co-array '(-177 -269 1123 866))
-        'MissingWidth 255
-        'StemV 105
-        'StemH 45
-        'CapHeight 660
-        'XHeight 394
-        'Ascent 720
-        'Descent -270
-        'Leading 83
-        'MaxWidth 1212
-        'AvgWidth 478
-        'ItalicAngle 0))
+ (co-io 9 0
+        (make-co-dict
+         'Type 'FontDescriptor
+         'FontName 'FiraSansOTMedium
+         'FontFile3 (co-io-ref 10 0)
+         'Flags 4
+         'FontBBox (co-array '(-177 -269 1123 866))
+         'MissingWidth 255
+         'StemV 105
+         'StemH 45
+         'CapHeight 660
+         'XHeight 394
+         'Ascent 720
+         'Descent -270
+         'Leading 83
+         'MaxWidth 1212
+         'AvgWidth 478
+         'ItalicAngle 0))
 
-(co-io 10 0 (make-font-co-stream "fira.otf"))
+ (co-io 10 0 (make-font-co-stream "fira.otf")))
diff --git a/pitfall/pitfall/render.rkt b/pitfall/pitfall/render.rkt
index ebf0e4fe..256483a5 100644
--- a/pitfall/pitfall/render.rkt
+++ b/pitfall/pitfall/render.rkt
@@ -20,8 +20,10 @@
        (~r #:min-width 10 #:pad-string "0" (cdr loc))) sep #:after-last sep))
  }))
 
-
 (define (render-args . args)
+  (render-list args))
+
+(define (render-list args)
   (define-values (bstrs offset locs)
     (for/fold ([cobstrs null]
                [offset 0]