How to Cut a Triangle in Car Window Film by Yourself?
2 Answers
First, determine the position and make marks. For the best effect, the left side should be larger than the right side, but making the right side the same size as the left will not have a significant impact. Press down with a ruler (preferably a flexible one with some stiffness) and use a small knife to make multiple passes along the ruler from top to bottom, ensuring it is completely cut. Start the cut from the top edge of the window and pull downward. You can leave a layer of transparent film and only remove the colored top layer.
To cut your own triangle, first prepare the tools. I used a utility knife and clear tape. Find a plastic triangle ruler or cardboard as a template, then trace the outline on the window film based on the rearview mirror position. Sitting in the driver's seat to repeatedly adjust the position is crucial—the base of the triangle should be two fingers' width from the window frame, and the height should ensure the entire mirror surface is visible. Use a marker to lightly sketch the lines; I prefer marking the three corner points with the knife tip first before connecting them. When cutting, hold the blade at a 30-degree angle for the smoothest cut, making three light passes from the center outward—only cutting through the film without scratching the glass. Before peeling, spray soapy water for lubrication, lift a small corner with your nail, and slowly peel. Finally, wipe off adhesive residue with alcohol swabs and smooth rough edges with a squeegee. Always use a fresh blade—old ones tend to leave jagged edges.