We made these trailing letters across several glass panels above the ESL book section in our junior high school library.
The lettering, cut using a Cricut machine were affixed to a glass panel separating the library from an adjacent pathway to the adjoining computer lab.
(TIP: We used a hot glue gun to glue the lettering to the glass. Hot glue is great for sticking items to glass as it usually pulls of quite easily. The pieces that don't pull off come off with a flick of a paint scraper. Residue comes off easily with a good window cleaner.)
TIP: For items you'd like to use again, put a piece of heavy bookbinding tape on the back, and use hot glue only on those areas. This will protect your item from damage when you take it down.