What happens next?

How to make venetian plaster
Wear a protective facemask to prevent inhaling the lime and marble dust.
Get a large plastic bucket or a wheelbarrow to use for making the venetian plaster.
Pour 2 quarts (1.89 liters) of lime putty into the bucket.
Add 2 quarts (1.89 liters) of marble dust to the bucket and stir with a mixing rod or a wooden stick. You can get a wooden stick free at any paint store.