Hi Tambo,
The paperclip is used very loosely indeed, and picture side down to the application form, so no damage can occur at all.
Oj's suggestion is a good 'un too.......i do send them in a jiffy protected envelope, as you need to send in the current/expired passport for them to cancel, and always send next day Special Delivery guaranteed to arrive before 1.00pm
When you do this. pusskin, you can track the progress and arrival of the package to the Passport Office by Royal Mail Track and Trace, simply by entering the 13 digit reference number your post office will print off for you when you send it. That way your also covered it does get lost in the post too.
Here's a link.....
http://www.royalmail.com/trackdetails
All the best,puss
yoges xx