Karen is using acrylic that is 0.1 inches thick. You could also use 1/8 inch or a similar thickness. You don’t want to go to thin, because then it might break. You don’t want to go too thick because it’ll be difficult to deal with. When deciding the size of your acrylic, you want to stick around two to three inches in either rectangular or square. If you go too big, the light of your LED won’t reach your design, and it won’t light up very well. For this particular application, if you’re only using one LED, then you want a smaller design. When drawing your design, you want to make sure that your lines are not going to be too thin because there will not be enough mass to catch the light significantly to really show off your design. When you make your design you want to make sure that you’re using nice, bold lines. Karen draws extra lines within the border of the acrylic. This is because when it’s done, she’s going to be putting aluminum tape around the edges, and this is to make sure that the design isn’t covered up later. When her design is done, she tapes the acrylic down so that it doesn’t shift, and so she can get good alignment between the acrylic and her design. Next, you’re going to want to etch your design. You can use an exacto blade or any kind of hobby knife that has a sharp pointy end. She suggests using electric etchers if you have a child doing this. For her example, she etched in a few different techniques so she could show you the differences of direction of scratch and how it affects your design when you place your LED. She goes over some of her different etching techniques. She suggests doing cross hatching, if you don’t have a specific design in mind. Scratch in opposing directions so that no matter where you place the light, it’ll still catch it. She recommends, though it’s not required, cutting a little notch in the edge of your acrylic to hold your LED in place and to keep the light pointing exactly where you want. S