diff --git a/libarchive/archive_write_open.3 b/libarchive/archive_write_open.3
index a52959b..457873e 100644
--- a/libarchive/archive_write_open.3
+++ b/libarchive/archive_write_open.3
@@ -66,6 +66,7 @@
 This is the most generic form of this function, which accepts
 pointers to three callback functions which will be invoked by
 the compression layer to write the constructed archive.
+This does not alter the default archive padding.
 .It Fn archive_write_open_fd
 A convenience form of
 .Fn archive_write_open
@@ -123,12 +124,21 @@
 You should be careful to ensure that this variable
 remains allocated until after the archive is
 closed.
+This function will disable padding unless you
+have specifically set the block size.
 .El
 More information about the
 .Va struct archive
 object and the overall design of the library can be found in the
 .Xr libarchive 3
 overview.
+.Pp
+Note that the convenience forms above vary in how
+they block the output.
+See
+.Xr archive_write_blocksize 3
+if you need to control the block size used for writes
+or the end-of-file padding behavior.
 .\"
 .Sh CLIENT CALLBACKS
 To use this library, you will need to define and register
@@ -226,6 +236,7 @@
 .Xr tar 1 ,
 .Xr libarchive 3 ,
 .Xr archive_write 3 ,
+.Xr archive_write_blocksize 3 ,
 .Xr archive_write_filter 3 ,
 .Xr archive_write_format 3 ,
 .Xr archive_write_new 3 ,