I'm so happy that Happy Celebrations and the Celebrations Duo Embossing Folders are in the new 2017-18 Annual Catalog! They were some of the first things I ordered from the Occasions Catalog. Sometimes the card stock will "crack" when it's embossed with the folders, but I had heard that using the Thick Whisper White helped. Here are the results of my experiment:
Regular Whisper White card stock. You can see the "cracks" around HAPPY. Stamping over them really makes them show up.
Thick Whisper White card stock. Still a few lines, but not as noticeable, so it does help!
You could also spritz your card stock with a little bit of water to soften the fibers before you put it in the embossing folder.
Colors: Basic Black, Emerald Envy, Sweet Sugarplum, Whisper White