The Blank Gift Card is an item that was released at Build-a-Bear Workshop during 2017.
Official Description Edit
"Make a beary special gift for your loved one with this embroidered gift tag! Personalize any stuffed animal gift from Build-A-Bear Workshop with a beary special Gift Tag. Embroider a name up to 10 character and attach it to the Red or White Floral Bouquets (sold separately.)" 
The Blank Gift Tag is a black embroidered gift tag. On the bottom right corner of the Blank Gift Tag a small red heart shaped paw can be seen.