Cookie Cutter Ice Windows
With a deep cookie tray and cookie cutters, you can make an ice window that looks great in daylight or with illumination at night.
Jen Hedberg's excellent book, Ice Luminary Magic, provided the inspiration for this method, but in reverse. She shows how to use cookie cutters to make ice shapes. By switching which ice is saved and which is discarded, I make cookie-cutter shaped holes in ice windows.
The "trick" is to keep as much water as possible out of the interior of the cookie cutters while freezing the ice in the tray. This is accomplished by starting with the tray, the cookie cutters, and the water as cold as possible. Then you pour a very thin layer of water carefully around the cookie cutters. Leave it to freeze. Keep more water at near-freezing temperatures and pour additional layers, letting each one freeze around the cookie cutters.
When the ice is thick enough (usually five to eight layers), set the cookie tray on bubble wrap in the bathtub and release the sheet of ice. Sometimes it works to just twist the tray a bit, but it may be necessary to pour a little hot water over the bottom. I set the tray aside to use later for carrying the ice sheet. If you're lucky, there is little or no ice inside the shapes, but usually you have to melt out a thin layer. For that, I use a focused spray of hot water aimed into the cookie cutter while the sheet is held upright. The hot water also helps loosen the cookie cutter so that it can be slid out.
I'll generally slide the sheet of ice gently back into the tray after removing the cookie cutters. At that point, it's possible to put it back outdoors with a bit of fresh ice-cold water to re-freeze. That produces a solid ice window that usually has the design in clear ice while the rest of the sheet is milky white.
Sometimes the result of adding back water is to make a ghostly image. The main point of producing a solid sheet of ice is to be able to assemble four sheets into a square to make a large luminary with a candle in the middle, while protecting the candle from the wind. For display as just a sheet standing up on end, I usually leave the holes open.
To add depth to the ice window, I often add ice appliques made in silicone baking pans like this one. They can be "welded" in place by wetting them in ice water and touching them to the surface of the ice sheet.