Measure the dimensions of your mirror. Use a tape measure to get accurate length and width measurements.
Go to your local custom frame shop or hobby shop that sells picture frame pieces. Give the framer your mirror measurements and ask him to cut unpainted, wide frame boards for your chunky modern mirror frame.
Dry fit the pieces together at home and place against the mirror to double check your measurements and cuts. The frame will sit on top of the mirror along the edges.
Place the frame pieces on a flat, covered surface and flip these over so that the backside is facing upwards.
Brush the inner edge of the frame with your paint color, bringing the color down about an inch along what will be the back of the frame. This insures that the reflection of the edge of your frame is the painted color when installed.
Flip all the frame pieces over to the front side and paint with your chosen paint color. Use a synthetic brush and smooth strokes to achieve a professional looking finish. Allow to dry before applying a second coat.
Apply a multi-purpose construction adhesive to the back of the mirror pieces. Apply carefully and stay away from the edges to avoid having excessive glue damage your frame or wall.
Assemble the frame on the glass. Start with the bottom piece, then the sides and, lastly, the top. Adjust slightly as needed to get the edges to perfectly fit together.
Press firmly against the glass and secure with pieces of painter’s tape to hold in place while curing.
Touch up the edges as needed with a small brush and your frame paint color.