For an event, we needed signs with the logos of our sponsors. We decided a good way to do this was by using layers of paint on acrylic, and perfected of laser engraved acrylic sign making.
Preparing The Acrylic
The first step is to paint your sheet of acrylic the color of our the logo’s background. For all our signs, we used a white background, so we started by painting the entire back side of the 12″x24″ sheets with Rust-Oleum white spray paint. Three thin coats are better than a heavy coat.
The next step is to setup the file in CorelDraw. Use the bitmap trace feature in CorelDraw to convert your logo’s image to curves. Its important to remember to mirror your graphic because you are engraving on the back of the sign. Each layer corresponds to a different color . For example, if you were doing red green and blue, you would separate your graphic into the 3 layers, one for each color. Turn whatever color the image is to black to ensure the laser uses full power.
The acrylic is far out of square, so we will be cutting out a box to establish the shape of our sign. We will do a rectangular sign with rounded edges. The is cut in the last step to keep the position of the piece constant when it is placed back in the laser for other layers.
Engraving Acrylic Sign
Now the laser comes in, laser engrave layer 1 into the back of the acrylic so all of the white paint in the affected areas is removed. If you can, have the laser set to bottom up engraving. This will prevent a white powdery substance from clouding your freshly engraved acrylic. Paint the engraved region the corresponding color with a hand paint. Spray paint doesn’t work for these steps as it results in a chemical reaction with the acrylic, and leaves a cracked finish.
Put it back in the laser and continue this process for the remaining layers, allowing to dry between colors. (Drying can be sped up with a heat gun)
A high detail logo remains on the other side of the acrylic. An optional last step is to clear coat the painted side to prevent scratches in the paint. A 3D printed bracket is useful to mount the engraved acrylic sign to a wall.