My DH and i own a dental lab (any dentists out there?) in my free time I like to blow out the eggs and use the dental handpiece (drill) and carve designs in the eggs. They can be very fragile to work on but its fun to work out the design for each egg.
. If I dont plan the pattern well I can end up cutting away something that ruins the whole egg OR I cut myself into an area that will make a piece fall out. I got an ostrich egg once and had a blast with it but after doing chicken and duck eggs i was a little intimidated by such a large canvas! I tried to use a dremel tool but they seem to have to much vibration for the delicate egg shell. I now use a high speed drill with fine burs and suction. They smell like burning feathers when I drill on them!!
