I also use foam core boards between my layers and hammer a sharpened wooden dowel all the way to the bottom until it cannot go any further. Before hammering them through, I measure the height of the cake and cut the dowel 1" shorter. I counter sink it with a smaller piece of dowel and put a icing "plug" where the hole is. I get them from the craft section at Walmart or the wooden dowel section from Lowes or Home Depot.I have NEVER had a cake slide (knock on wood) when...
Don't quote me on this, but I have not seen white edible ink. I have an edible image printer and none of the ink cartridges are white. I'm sorry but other than that, I don't have an answer to your question.Anyone out there that can actually help??
If you have an air brush machine you can spray it with a coat of pearl shimmer. I don't use buttercream, only non dairy whipped topping (Pastry Pride) and it looks lovely. Also, I think I've seen areosol cans of shimmer on line at many cake supply websites if you don't have an air brush machine.If you want it shiny, I've also seen online cans of spray edible laquer.I hope that helps!
My trick is to bend the wire into an "L" down towards the end, about 1 inch from the end. This stops it from swaying around. Then dip it in chocolate and let dry. And poke it into the cake, then give it a 1/4 turn. It works every time!