Apply a light base color to the wall.
Make plaster of paris look like marble.
Use a sample of marble or a picture as reference.
Keep in mind you ll want to fill your container up enough to be able to dip the vase inside without the plaster overflowing.
Use a small paintbrush to add veins which should be thin and random.
And if you can buy plaster pigments that would be another good thing for you.
To create a marble like venetian plaster effect in your space you can use inexpensive paint and faux treatment tools for a fraction of the price of paying a professional plasterer.
And if you can get acrylic liquid polymer you can use clear shoe polish and you can polish the things you make and they will look amazing.
Avoid following a pattern when painting the veins.
How to create a faux venetian plaster look.
Following the instructions on the plaster of paris container mix your plaster.
Use this plaster within 15 minutes and let it set 3 days to completely dry.
Acrylic polymer is white liquid it looks like milk it is mixed with water if you want at a rate of one to one.
Or you can use it neat.
The resulting plaster will have a soupy consistency.
To obtain a natural look for the veins get a dry sponge and gently tap the veins making the color blend with the ones underneath.
To make plaster of paris with glue instead of flour heat 1 cup 240 ml of water to 100 f 38 c.