We first covered an oval on the front of an ostrich egg using an oval of paper and masking tape to protect the area we wanted to etch from any overspray of hair spray.

Next we sprayed all around the outside of the oval where we wanted to retain the shiny layer of the ostrich egg.

After the hairspray was dry we removed the paper oval and then masked up our experimental design using blue micro masking tape.

Note: the blue micro masking tape is available in different widths and is perfect for marking lattice and other designs on an egg.

http://www.jammydog.com/

We placed the prepared egg into an ice cream container with masking tape to hold the egg in position. Fresh vinegar was added to about half way up the shell and left aside for about 2 hours.

On removing the egg from the vinegar bath we were delighted to see that the masking tape had held up to standing in vinegar for this length of time and the etching had worked as we had hoped.

The vinegar had removed the hard shiny surface of the ostrich egg but had not encroached on the area we had sprayed with hairspray.

The only thing we did wrong in our excitement to try out this idea was forgetting to put some blu tac in the centre of the shell or some other means of keeping the egg off the bottom of the container and this left a small area in the middle of the shell which wasn't etched as deeply as the rest of the experimental area.