Six Lab Testing Greeting Cards. This best selling Lab Testing card is extremely popular with anyone who owns a Black Labrador or who loves dogs! One of the best selling cards in our range, it's blank inside so it can be used for any occasion. • Size: The card is 25.4 ants long x 35.6 ants long. Or, for those who don’t work in ant sizing, it’s 5”x7” (127mm X 178mm). • Professionally printed onto heavyweight card stock: 300gsm ivory hammered card. The card comes with a recycled brown envelope and is wrapped in a cellophane sleeve.