diff --git a/luametalatex-back-pdf.lua b/luametalatex-back-pdf.lua
index 7e03f8a..bb2eba4 100644
--- a/luametalatex-back-pdf.lua
+++ b/luametalatex-back-pdf.lua
@@ -75,10 +75,9 @@ local function write_infodir(p)
   return p:indirect(nil, string.format("<<%s%s>>", infodir, additional))
 end
 
-local function pdf_string(s)
-  -- Emulate other engines here: If  looks like an escaped string, treat it as such. Otherwise, add parenthesis.
-  return s:match("^%(.*%)$") or s:match("^<.*>$") or '(' .. s .. ')'
-end
+local pdf_escape = require'luametalatex-pdf-escape'
+local pdf_bytestring = pdf_escape.escape_bytes
+local pdf_text = pdf_escape.escape_text
 
 callback.register("stop_run", function()
   if not pfile then
@@ -185,7 +184,7 @@ local function get_action_attr(p, action, is_link)
   local action_attr = is_link and "/Subtype/Link/A<<" or "<<"
   local file = action.file
   if file then
-    action_attr = action_attr .. '/F' .. pdf_string(file)
+    action_attr = action_attr .. '/F' .. pdf_bytestring(file)
     local newwindow = action.new_window
     if newwindow and newwindow > 0 then
       action_attr = action_attr .. '/NewWindow ' .. (newwindow == 1 and 'true' or 'false')
@@ -199,7 +198,7 @@ local function get_action_attr(p, action, is_link)
     local id = action.id
     if file then
       assert(type(id) == "string")
-      action_attr = action_attr .. "/S/GoToR/D" .. pdf_string(id) .. ">>"
+      action_attr = action_attr .. "/S/GoToR/D" .. pdf_bytestring(id) .. ">>"
     else
       local dest = dests[id]
       if not dest then
@@ -207,7 +206,7 @@ local function get_action_attr(p, action, is_link)
         dests[id] = dest
       end
       if type(id) == "string" then
-        action_attr = action_attr .. "/S/GoTo/D" .. pdf_string(id) .. ">>"
+        action_attr = action_attr .. "/S/GoTo/D" .. pdf_bytestring(id) .. ">>"
       else
         action_attr = string.format("%s/S/GoTo/D %i 0 R>>", action_attr, dest)
       end
@@ -577,11 +576,11 @@ token.luacmd("pdfextension", function(_, imm)
       local level = token.scan_int()
       local open = token.scan_keyword'open'
       local title = token.scan_string()
-      outline:add(pdf_string(title), action, level, open, attr)
+      outline:add(pdf_text(title), action, level, open, attr)
     else
       local count = token.scan_keyword'count' and token.scan_int() or 0
       local title = token.scan_string()
-      outline:add_legacy(pdf_string(title), action, count, attr)
+      outline:add_legacy(pdf_text(title), action, count, attr)
     end
   elseif token.scan_keyword"dest" then
     local id
diff --git a/luametalatex-nodewriter.lua b/luametalatex-nodewriter.lua
index 438f5d9..5e6a331 100644
--- a/luametalatex-nodewriter.lua
+++ b/luametalatex-nodewriter.lua
@@ -324,7 +324,8 @@ function nodehandler.glue(p, n, x, y, outer, origin, level) -- Naturally this is
 end
 function nodehandler.kern() end
 function nodehandler.penalty() end
-local literalescape = lpeg.Cs((lpeg.S'\\()\r'/{['\\'] = '\\\\', ['('] = '\\(', [')'] = '\\)', ['\r'] = '\\r'}+1)^0)
+
+local pdf_escape = require'luametalatex-pdf-escape'.escape_raw
 local match = lpeg.match
 local function do_commands(p, c, f, fid, x, y, outer, ...)
   local fonts = f.fonts
@@ -407,20 +408,20 @@ function nodehandler.glyph(p, n, x, y, ...)
     -- if f.encodingbytes == -3 then
     if false then
       if index < 0x80 then
-        p.pending[#p.pending+1] = match(literalescape, string.pack('>B', index))
+        p.pending[#p.pending+1] = pdf_escape(string.pack('>B', index))
       elseif index < 0x7F80 then
-        p.pending[#p.pending+1] = match(literalescape, string.pack('>H', index+0x7F80))
+        p.pending[#p.pending+1] = pdf_escape(string.pack('>H', index+0x7F80))
       else
-        p.pending[#p.pending+1] = match(literalescape, string.pack('>BH', 0xFF, index-0x7F80))
+        p.pending[#p.pending+1] = pdf_escape(string.pack('>BH', 0xFF, index-0x7F80))
       end
     else
-      p.pending[#p.pending+1] = match(literalescape, string.pack('>H', index))
+      p.pending[#p.pending+1] = pdf_escape(string.pack('>H', index))
     end
     if not p.usedglyphs[index] then
       p.usedglyphs[index] = {index, math.floor(c.width * 1000 / f.size + .5), c.tounicode}
     end
   else
-    p.pending[#p.pending+1] = match(literalescape, string.char(getchar(n)))
+    p.pending[#p.pending+1] = pdf_escape(string.char(getchar(n)))
     if not p.usedglyphs[getchar(n)] then
       p.usedglyphs[getchar(n)] = {getchar(n), math.floor(c.width * 1000 / f.size + .5), c.tounicode}
     end
diff --git a/luametalatex-pdf-escape.lua b/luametalatex-pdf-escape.lua
new file mode 100644
index 0000000..8d87fe1
--- /dev/null
+++ b/luametalatex-pdf-escape.lua
@@ -0,0 +1,77 @@
+local mode = 6
+-- Control how much escaping is done... the mode is a bitset:
+-- Bit 0: Disable auto-detection of pre-escaped input
+-- Bit 1: Convert UTF-8 input to UTF-16
+-- Bit 2: Actually escape unescaped input instead of assuming that it is safe
+--
+-- This currently results in 8 modes. Mode 7 is recommended if you can control
+-- all new code, otherwise Mode 6 might be required. Code 0 is (mostly) compatible
+-- with other engines.
+--
+-- Also we have three distinct functions which relate to different uses.
+-- escape_text is for text strings and fully respects the mode.
+-- escape_bytes is for non-text byte strings and always acts as if Bit 1 is unset
+--    (after all, UTF-16 doesn't make sense for non-text strings)
+-- escape_raw always acts like mode 5 without the parens: Just escape, without any
+-- other auto-detection or conversion. (This is used for actual content text)
+local function setmode(new)
+  mode = new
+end
+local function is_escaped(s)
+  if mode & 1 == 1 then return false end
+  return (mode & 1 == 1) and (s:match("^%(.*%)$") or s:match("^<.*>$")) and true or false
+end
+local function to_utf16(s)
+  local i = 3
+  local bytes = {0xFE, 0xFF}
+  for _, c in utf8.codes(s) do
+    if c < 0x10000 then
+      -- assert(c < 0xD800 or c >= 0xE000)
+      bytes[i] = c >> 8
+      bytes[i+1] = c & 0xFF
+      i = i+2
+    else
+      c = c-0x10000
+      bytes[i] = 0xD8 | ((c>>18) & 3)
+      bytes[i+1] = (c>>10) & 0xFF
+      bytes[i+2] = 0xDC | ((c>>8) & 3)
+      bytes[i+3] = c & 0xFF
+      i = i+4
+    end
+  end
+  return string.char(table.unpack(bytes))
+end
+-- This is pretty much the minimal escaping possible: Only escape bytes which are 
+local l = lpeg
+local simple_char = 1-l.S'()\\'
+local semi_simple_char = simple_char + l.P'\\'/'\\\\'
+local nested = l.P{'(' * (semi_simple_char + l.V(1))^0 * ')'}
+local inner = (semi_simple_char + nested + (l.Cc'\\' * l.S'()'))^0 * -1
+local raw = l.Cs(inner)
+local patt = l.Cs(l.Cc'(' * inner * l.Cc')')
+local function escape_bytes(s)
+  if is_escaped(s) then return s end
+  if mode & 4 == 0 then
+    return '(' .. s .. ')'
+  end
+  return patt:match(s)
+end
+local function escape_text(s)
+  if is_escaped(s) then return s end
+  if mode & 2 == 2 then
+    s = to_utf16(s)
+  elseif mode & 4 == 0 then
+    return '(' .. s .. ')'
+  end
+  return patt:match(s)
+end
+local function escape_raw(s)
+  return raw:match(s)
+end
+
+return {
+  escape_raw = escape_raw,
+  escape_bytes = escape_bytes,
+  escape_text = escape_text,
+  setmode = setmode,
+}
diff --git a/luametalatex-pdf-nametree.lua b/luametalatex-pdf-nametree.lua
index 8ddab33..ccf3b98 100644
--- a/luametalatex-pdf-nametree.lua
+++ b/luametalatex-pdf-nametree.lua
@@ -14,10 +14,9 @@ local function write(pdf, tree, escaped, step)
   move(tree, #tree+1, 2*#tree-nextcount, nextcount+1)
   return write(pdf, tree, escaped, step*6)
 end
-local function pdf_string(s)
-  -- Emulate other engines here: If  looks like an escaped string, treat it as such. Otherwise, add parenthesis.
-  return s:match("^%(.*%)$") or s:match("^<.*>$") or '(' .. s .. ')'
-end
+
+local pdf_bytestring = require'luametalatex-pdf-escape'.escape_bytes
+
 local serialized = {}
 return function(values, pdf)
   local tree = {}
@@ -35,7 +34,7 @@ return function(values, pdf)
       local key = tree[6*i+j]
       if key then
         local value = values[key]
-        key = pdf_string(key)
+        key = pdf_bytestring(key)
         tree[6*i+j] = key
         serialized[2*j-1] = key
         serialized[2*j] = value
diff --git a/luametalatex-pdf.lua b/luametalatex-pdf.lua
index b971bbc..0d0e88c 100644
--- a/luametalatex-pdf.lua
+++ b/luametalatex-pdf.lua
@@ -14,7 +14,8 @@ local function written(pdf, num)
   if not num or num == assigned then return end
   return num ~= delayed
 end
-local function stream(pdf, num, dict, content, isfile)
+-- raw: Pass on preencoded stream. Currently ignored.
+local function stream(pdf, num, dict, content, isfile, raw)
   if not num then num = pdf:getobj() end
   if pdf[num] ~= assigned then
     error[[Invalid object]]