diff --git a/.local/bin/scripts/sign b/.local/bin/scripts/sign
index 36f4b28..ca802c0 100755
--- a/.local/bin/scripts/sign
+++ b/.local/bin/scripts/sign
@@ -1,5 +1,7 @@
 #!/bin/sh
-signature=$(pass information/signature)
+test -r "$1" || (echo "Usage: sign <document.pdf> [hoffset [voffset [scale [alt-signature]]]]" && exit 1)
+
+signature=$(pass information/signature$(test -n "$5" && echo "-$5"))
 
 # TODO make filenames unique and don't rerun unneccessarily
 tmp_base=/tmp/sign
@@ -7,14 +9,14 @@ mkdir -p $tmp_base
 tmp_signed=$tmp_base/$1_last-signature.pdf
 tmp_reversed=$tmp_base/$1_reverse.pdf
 sig=$tmp_base/signature_offset.pdf
-result="${1%.pdf}_signed.pdf"
+result="${1%.pdf}_${5:-signed}.pdf"
 
 pdfjam "$signature" --outfile "$sig" --papersize "{595pt, 842pt}" --noautoscale true \
     --offset "${2:-0}pt ${3:-0}pt" --scale "${4:-1}"
 pdfjam "$1" last "$sig" --outfile "$tmp_signed" --delta "0 -842pt" --nup "1x2" --fitpaper true
 
 # https://apple.stackexchange.com/questions/198854/shell-command-to-count-pages-in-a-pdf-other-than-pdftk
-if test $(pdftk "" dump_data | grep Pages | cut -d' ' -f2) -gt 1
+if test "$(pdftk "$1" dump_data | grep Pages | cut -d' ' -f2)" -gt 1
   then
     pdfjam "$1" last-1 --outfile "$tmp_reversed"
     pdfjam "$tmp_reversed" last-2 "$tmp_signed" --outfile "$result"