Buy a picture frame in the size you prefer. The best size is 5x7 inches or double that. This is because it needs to be practical and easy to handle, and a larger object is just likely to slip out of your hand, often at the wrong time. The transparent surface can be made of plastic, because it is easier to handle and is safer (it is an object that often risks falling). But it should be the only part in plastic, the frame and the bottom should be wood or metal.

Many reject the plastic surface and prefer glass because it is a more "noble" material. I tend to support this point of view, but I prefer to avoid glass pieces everywhere. Also, the effort to safeguard the integrity of the mirror becomes a significant source of distraction during rituals. During the ritual, the mirror can fall, tip over, slide, hit any surface, but this should not be a worry or a distraction for you - it becomes a worry if it is made of glass. The best shape is a rectangle, with the classic support on the back. If it's your first black mirror, I simply recommend a wooden frame with a transparent plastic surface. Over time, you can change and prefer something better, more noble and elaborate, or just more decorative or evocative. Over time, noticing the differences between ritual and ritual, you can also have more than one black mirror - one with a plastic surface, unbreakable and easy to handle, and one for example of metal and glass for those rituals where you are now sure that the mirror will not move from its position.

For the black color, buy a concentrated black paint dye from a hardware store. All you have to do is remove the clear "glass" of the frame, drip the black dye and let it dry, and then reassemble the frame.

If there are any protective films, remove them first. Drip the dye and let it slide over the surface is the best way to avoid marks or traces of any kind, and to create a uniform, smooth and deep black surface. Place the "glass" flat on a sheet of plastic or something else that you can get dirty, drip the dye and then grab this base to tilt the "glass" and slide the dye across the entire surface, without ever holding the "glass" in your hand to avoid smudging or fingerprints along the edges. Drop more drops of dye to fill in any gaps. Be careful with the amount of dye, because often a small amount is needed to cover the entire surface, if you slide it well. Too much dye will create black clumps and waves that are difficult to manage.

Let the dye dry well - 24 or 48 hours - and then reassemble the frame, leaving the colored surface on the back, in contact with the bottom, to protect it and not touch it again. Clean the front surface well, and check that you have obtained a deep and clear black surface, without defects of any kind. In this case, you can try adding more dye, and in the worst case (irreparable defects such as trapped impurities) you should start over with a new frame.

This should be done during the day, on a beautiful sunny day. If this is not possible, take the newly created black mirror with you - but before "activating" it - outside, on a sunny afternoon, in a natural and flourishing context (for example a park full of people). Expose the black mirror to the sun and reflect your face inside its blackness. Smile at the new dark door you have created to suppress the world of light around you.

That will be - and must be - the only and last time your black mirror will see the light of the sun.