You can use a standard alphabet for lettering and convert the stitch type to a chenille fill. Alphabets are usually digitized using Input A, so you cannot automatically add borders with Compound Chenille. You need to add a border either manually or adding a Compound Chenille object.
To convert lettering objects to chenille
1. Select a lettering object. 2. Click the Coil or Straight icon 3. Add a border to hold the stitches in place, if required.