To get started with the 3D printing process first download the 3D model file that will be in the .stl format. The file has been included with this instructable for your convenience. After downloading the file (Nail Polish Applicator v2), open up any 3D printing software and import the file to the program. For this demonstration the model is going to be printed with an open source free 3D printing program called Cura. Download Cura at this link: https://ultimaker.com/en/products/ultimaker-cura-software . After downloading and installing Cura go ahead and you'll be prompted to pick the 3D printer you have. Go ahead and add the printer. Next Click on the folder that's on the left side tool bar. Open your 3D model and rotate it like so in picture 3. After that click prepare and save the file. Since every 3D printer is different you will have to find instructions on how to get your printer started, but you will have the ready to go 3D printable file. Once printed go to step 1.
Step 1: Orientation and Unscrewing Bottle
With the Nail Polish Applicator (NPA) printed we can begin with painting nails. First, the NPA needs to be oriented correctly. Set the fatter end with the rounded hole on a flat surface. Now place your bottle into the hole. Place your hand onto NPA while also grabbing the top of the bottle. Unscrew while putting pressure into the NPA for stability.
Step 2: Applying Nail Polish
Now that the nail polish cap/brush is off or loose, take the bottle out of the hole and put it to the side. Take the brush and put it into the hole at the top of the NPA. the brush should slide through with minimal paint loss. Now drag your finger across the brush or however which way is comfortable.
(helpful tip) : find a way to secure the NPA to reduce sliding and instability.