diff --git a/luametalatex-lateinit.lua b/luametalatex-lateinit.lua
index 2af1370..70c37bf 100644
--- a/luametalatex-lateinit.lua
+++ b/luametalatex-lateinit.lua
@@ -11,9 +11,6 @@ status.safer_option = 0 -- compat
 status.shell_escape = 0 -- compat -- This is currently a lie.
 -- require'module' -- ???
 pdf = {
-  getfontname = function(id) -- No font sharing yet (TODO)
-    return id
-  end,
   variable = {},
 }
 require'luametalatex-font-resolve' -- Replace font.define. Must be loaded before callbacks
diff --git a/luametalatex-nodewriter.lua b/luametalatex-nodewriter.lua
index 67d78fe..92cdffd 100644
--- a/luametalatex-nodewriter.lua
+++ b/luametalatex-nodewriter.lua
@@ -31,6 +31,7 @@ local rangedimensions = direct.rangedimensions
 local traverse_id = direct.traverse_id
 local getdata = direct.getdata
 
+local pdf_font_map = require'luametalatex-pdf-font-deduplicate'
 local get_whatsit_handler = require'luametalatex-whatsits'.handler
 
 local dir_id = node.id'dir'
@@ -95,10 +96,10 @@ local function totext(p, fid)
   local f = font.getfont(fid) or font.fonts[fid]
   if last ~= text then p.strings[#p.strings+1] = "BT" p.pos.lx, p.pos.ly, p.pos.x, p.pos.y, p.font.exfactor, p.font.extend, p.font.squeeze, p.font.slant = 0, 0, 0, 0, 0, 1, 1, 0 end
 
-  if not f.parent then f.parent = pdf.getfontname(fid) end
-  p.resources.Font[fontnames[f.parent]] = p.fontdirs[f.parent]
-  p.strings[#p.strings+1] = format("/F%i %f Tf 0 Tr", f.parent, sp2bp(f.size)) -- TODO: Setting the mode, width, etc.
-  p.font.usedglyphs = p.usedglyphs[f.parent]
+  local pdf_fid = pdf_font_map[fid]
+  p.resources.Font[fontnames[pdf_fid]] = p.fontdirs[pdf_fid]
+  p.strings[#p.strings+1] = format("/F%i %f Tf 0 Tr", pdf_fid, sp2bp(f.size)) -- TODO: Setting the mode, width, etc.
+  p.font.usedglyphs = p.usedglyphs[pdf_fid]
 
   p.font.fid = fid
   p.font.font = f
diff --git a/luametalatex-pdf-font-cff.lua b/luametalatex-pdf-font-cff.lua
index 980de5b..f6db785 100644
--- a/luametalatex-pdf-font-cff.lua
+++ b/luametalatex-pdf-font-cff.lua
@@ -580,7 +580,7 @@ end
 -- local buf = file:read'a'
 -- file:close()
 -- io.open(arg[3], 'w'):write(myfunc(buf, 1, 1, nil, {{3}, {200}, {1000}, {1329}, {1330}, {1331}})):close()
-return function(filename, encoding) return function(fontdir, usedcids)
+return function(filename, fontid, encoding) return function(fontdir, usedcids)
   local file = io.open(filename)
   local buf = file:read'a'
   local i = 1
@@ -589,12 +589,12 @@ return function(filename, encoding) return function(fontdir, usedcids)
   if magic == "ttcf" or magic == "OTTO" then
     -- assert(not encoding) -- nil or false
     encoding = encoding or false
-    local magic, tables = sfnt.parse(buf, 1) -- TODO: Interpret widths etc, they might differ from the CFF ones.
+    local magic, tables = sfnt.parse(buf, fontid) -- TODO: Interpret widths etc, they might differ from the CFF ones.
     assert(magic == "OTTO")
     -- Also CFF2 would be nice to have
     i = tables['CFF '][1]
   end
-  local content, bbox = myfunc(buf, i, 1, usedcids, encoding)
+  local content, bbox = myfunc(buf, i, fontid, usedcids, encoding)
   fontdir.bbox = bbox
   return content
 end end
diff --git a/luametalatex-pdf-font-deduplicate.lua b/luametalatex-pdf-font-deduplicate.lua
new file mode 100644
index 0000000..4a08d20
--- /dev/null
+++ b/luametalatex-pdf-font-deduplicate.lua
@@ -0,0 +1,44 @@
+require'luametalatex-font-resolve' -- Ensure that font.fonts exists
+
+local keymap = {}
+
+-- There are multiple criteria for sharing backend fonts:
+--  * Obviously encodingbytes have to be the same.
+--  * The filename better is the same too.
+--  * Similarly the index must be the same.
+--  * Specifically in the PK font case *without* fixed DPI,
+--    The size must be the same too.
+--  * For fontmap based fonts, compare the name field instead,
+--    of the normal filename, especially to capture encoding differences.
+--    An alternative might be to only take the encoding into account.
+--    This is also required for other fonts which might not be backed by
+--    traditional files
+local function build_sharekey(fontdir)
+  local encodingbytes = assert(fontdir.encodingbytes)
+  local key = string.format("%i:%s:", fontdir.encodingbytes, fontdir.format)
+  if encodingbytes == 1 then
+    if fontdir.format == "type3" then
+      return string.format("%s%i:%s", key, fontdir.size, fontdir.name)
+    end
+    key = string.format("%s%s:", key, fontdir.encoding or '')
+  end
+  key = string.format("%s%i:%s", key, fontdir.subfont or 1, fontdir.filename)
+  return key
+end
+
+local fonts = font.fonts
+local fontmap = setmetatable({}, {
+  __index = function(t, fid)
+    local key = build_sharekey(assert(fonts[fid]))
+    local mapped = keymap[key]
+    local share_parent = mapped and t[mapped] or fid
+    t[fid] = share_parent
+    return share_parent
+  end,
+})
+
+function pdf.getfontname(fid)
+  return fontmap[fid]
+end
+
+return fontmap
diff --git a/luametalatex-pdf-font.lua b/luametalatex-pdf-font.lua
index 331873e..70f5ed3 100644
--- a/luametalatex-pdf-font.lua
+++ b/luametalatex-pdf-font.lua
@@ -181,7 +181,7 @@ local function buildfont0cff(pdf, fontdir, usedcids)
       if fontdir.format == "type1" then
         cff = require'luametalatex-pdf-font-t1'(fontdir.filename, fontdir.encoding)(fontdir, usedcids)
       elseif fontdir.format == "opentype" then
-        cff = require'luametalatex-pdf-font-cff'(fontdir.filename, fontdir.encodingbytes == 1 and (fontdir.encoding or true))(fontdir, usedcids)
+        cff = require'luametalatex-pdf-font-cff'(fontdir.filename, 1, fontdir.encodingbytes == 1 and (fontdir.encoding or true))(fontdir, usedcids)
       else
         error[[Unsupported format]]
       end
diff --git a/luametalatex-pdf-image-pdf.lua b/luametalatex-pdf-image-pdf.lua
index dcf57ac..2de3d67 100644
--- a/luametalatex-pdf-image-pdf.lua
+++ b/luametalatex-pdf-image-pdf.lua
@@ -74,7 +74,7 @@ function pdf_functions.write(pfile, img)
   local file = open_pdfe(img)
   local page = pdfe.getpage(file, img.page)
   local bbox = img.bbox
-  local dict = string.format("/Subtype/Form/BBox[%f %f %f %f]/Resources %s", bbox[1], bbox[2], bbox[3], bbox[4], pdfe_deepcopy(file, img.filepath, pfile, pdfe.getfromdictionary(page, 'Resources')))
+  local dict = string.format("/Subtype/Form/BBox[%f %f %f %f]/Resources %s", to_bp(bbox[1]), to_bp(bbox[2]), to_bp(bbox[3]), to_bp(bbox[4]), pdfe_deepcopy(file, img.filepath, pfile, pdfe.getfromdictionary(page, 'Resources')))
   local content, raw = page.Contents
   -- Three cases: Contents is a stream, so copy the stream (Remember to copy filter if necessary)
   --              Contents is an array of streams, so append all the streams as a new stream