Write Now. Read Later. Treasure Forever. Dad will truly treasure this keepsake forever. The twelve fold-and-mail-style envelopes (ten prompted, two blank) invite sons and daughters to capture memories and express gratitude for Dad, seal up the envelopes with the included stickers, and postdate the letters. When Dad breaks the seals in the future, he'll receive an invaluable gift: a tangible reflection of her child's love.