diff --git a/blender_asset_tracer/cli/common.py b/blender_asset_tracer/cli/common.py
index 3f9118a..d93fd78 100644
--- a/blender_asset_tracer/cli/common.py
+++ b/blender_asset_tracer/cli/common.py
@@ -1,4 +1,5 @@
 """Common functionality for CLI parsers."""
+import pathlib
 
 
 def add_flag(argparser, flag_name: str, **kwargs):
@@ -14,3 +15,9 @@ def add_flag(argparser, flag_name: str, **kwargs):
                            **kwargs)
 
 
+def shorten(cwd: pathlib.Path, somepath: pathlib.Path) -> pathlib.Path:
+    """Return 'somepath' relative to CWD if possible."""
+    try:
+        return somepath.relative_to(cwd)
+    except ValueError:
+        return somepath
diff --git a/blender_asset_tracer/cli/list_deps.py b/blender_asset_tracer/cli/list_deps.py
index c6ca5f9..49169a7 100644
--- a/blender_asset_tracer/cli/list_deps.py
+++ b/blender_asset_tracer/cli/list_deps.py
@@ -1,4 +1,5 @@
 """List dependencies of a blend file."""
+import functools
 import json
 import logging
 import pathlib
@@ -34,14 +35,7 @@ def cli_list(args):
 def report_text(bpath):
     reported_assets = set()
     last_reported_bfile = None
-    cwd = pathlib.Path.cwd()
-
-    def shorten(somepath: pathlib.Path) -> pathlib.Path:
-        """Return 'somepath' relative to CWD if possible."""
-        try:
-            return somepath.relative_to(cwd)
-        except ValueError:
-            return somepath
+    shorten = functools.partial(common.shorten, pathlib.Path.cwd())
 
     for usage in tracer.deps(bpath):
         filepath = usage.block.bfile.filepath.absolute()
diff --git a/blender_asset_tracer/cli/pack.py b/blender_asset_tracer/cli/pack.py
index ba6b017..76a9f8b 100644
--- a/blender_asset_tracer/cli/pack.py
+++ b/blender_asset_tracer/cli/pack.py
@@ -1,4 +1,13 @@
 """Create a BAT-pack for the given blend file."""
+import functools
+import logging
+import pathlib
+import shutil
+
+from blender_asset_tracer import tracer
+from . import common
+
+log = logging.getLogger(__name__)
 
 
 def add_parser(subparsers):
@@ -6,7 +15,47 @@ def add_parser(subparsers):
 
     parser = subparsers.add_parser('pack', help=__doc__)
     parser.set_defaults(func=cli_pack)
+    parser.add_argument('blendfile', type=pathlib.Path)
+    parser.add_argument('target', type=pathlib.Path)
 
 
 def cli_pack(args):
-    raise NotImplementedError('bat pack not implemented yet')
+    bpath = args.blendfile
+    if not bpath.exists():
+        log.fatal('File %s does not exist', args.bpath)
+        return 3
+
+    tpath = args.target
+    if tpath.exists() and not tpath.is_dir():
+        log.fatal('Target %s exists and is not a directory', tpath)
+        return 4
+
+    shorten = functools.partial(common.shorten, pathlib.Path.cwd())
+    already_copied = set()
+    for usage in tracer.deps(bpath):
+        if usage.asset_path.is_absolute():
+            raise NotImplementedError('Sorry, cannot handle absolute paths yet: %s' % usage)
+
+        for assetpath in usage.files():
+            try:
+                assetpath = assetpath.resolve()
+            except FileNotFoundError:
+                log.error('Dependency %s does not exist', assetpath)
+
+            if assetpath in already_copied:
+                log.debug('Already copied %s', assetpath)
+                continue
+            already_copied.add(assetpath)
+
+            relpath = shorten(assetpath)
+            if relpath.is_absolute():
+                raise NotImplementedError('Sorry, cannot handle absolute paths yet: %s in %s'
+                                          % (usage, assetpath))
+
+            full_target = tpath / relpath
+            full_target.parent.mkdir(parents=True, exist_ok=True)
+            # TODO(Sybren): when we target Py 3.6+, remove the str() calls.
+            print(relpath)
+            shutil.copyfile(str(assetpath), str(full_target))
+
+    log.info('Copied %d files to %s', len(already_copied), tpath)
diff --git a/blender_asset_tracer/tracer/file2blocks.py b/blender_asset_tracer/tracer/file2blocks.py
index e7c542b..283f720 100644
--- a/blender_asset_tracer/tracer/file2blocks.py
+++ b/blender_asset_tracer/tracer/file2blocks.py
@@ -35,7 +35,7 @@ class _BlockIterator:
                     limit_to: typing.Set[blendfile.BlendFileBlock] = frozenset(),
                     ) -> typing.Iterator[blendfile.BlendFileBlock]:
         """Expand blocks with dependencies from other libraries."""
-        bpath = bfile.filepath
+        bpath = bfile.filepath.absolute().resolve()
         root_dir = bpathlib.BlendPath(bpath.parent)
 
         # Mapping from library path to data blocks to expand.
@@ -79,6 +79,12 @@ class _BlockIterator:
         # and iterate over the blocks referred there.
         for lib_bpath, idblocks in blocks_per_lib.items():
             lib_path = lib_bpath.to_path()
+            try:
+                lib_path = lib_path.resolve()
+            except FileNotFoundError:
+                log.warning('Library %s does not exist', lib_path)
+                continue
+
             log.debug('Expanding %d blocks in %s', len(idblocks), lib_path)
 
             with blendfile.BlendFile(lib_path) as libfile: