Hi Pam. Congratulations on the big order. I make lots of unscented pillars, all sizes, shapes and colors. I've found that wicking is easy when you're not using fragrance oil or mineral oil. For example, a 2/0 square braid works great in all my unscented 3" round pillars no matter which wax or recipe I use. They don't curl or mushroom, so I can marathon burn without babysitting the wick. And as long as there's no draft, they don't get blow outs. As for safety issues, you mentioned they'd be placed on shelves on a wall. For one thing, wallboard and paint are flammable, so I'd be concerned about how close they'll be to the wall. Also, if a shelf is placed above another shelf, heat will build up from the candle below. A wood shelf could catch fire and if it's a glass shelf, the heat will make it crack. (Unfortunately I learned this the hard way.)