Not all luck-bringing papers are couplets. Some are four-character-phrases that express traditional sentiments for a rich and bountiful spring. Still others are single characters, for example, the Chinese character "fu", meaning luck, blessings, happiness and good fortune.
The character "fu" is everywhere during the festival. On the doors of shops and families and even in rooms, people like to paste high the "fu" character calligraphed on red paper.