Projection

The main use for the Tapestrum Arcanum is as the source of power for those magically aligned and capable of projecting their will into the Tapestry. Projecting, in simplest terms, is akin to manifesting one's thoughts but the mage doing the projecting actually experiences a traversal into the Tapestry and interacts with it even if hardly a blink of an eye passes on Nascindor.

Projection

It was discovered early on that, as the Tapestry is a mimicry of the real Nascindor, changes made within are reflected unto reality, often with enhanced intensity due to the malleable nature of matter within the Tapestry.

For example, picture a sorcerer in a room with an apple on a small table. He projects his presence into the Tapestry, walks up to the apple's counterpart and squeezes it into a small ball in his hand. This change is then immediately and violently reflected in the real Nascindor, where the sudden, massive pressure is applied to the real apple which will promptly implode upon itself.
It is perhaps fortunate, then, that humans and other living creatures do not naturally have a presence in the Tapestry. It would seem that one needs to actively project oneself into the Tapestry to appear there. However, this does not mean that a mage is incapable of harming those without a presence in the Tapestry, as they can still cause a wide variety of effects in the real world using their surroundings within the Tapestry. It is not unusual for walls of nearby buildings or rocks to shed sharp shards of stone that fling themselves at individuals or forceful gusts of air slamming into those who have slighted a wizard, with more drastic magic being reserved for actual battle and the intent to kill.

Further Uses

Of course, there are more esoteric uses than simple manipulation of matter. Sufficiently learned wizards can perceive the flow of time as it passes through the Tapestry as a kind of thread and, with a delicate hand, nudge it in one way or the other, causing time to either decelerate or accelerate for the briefest of moments. The truly gifted may even grasp this thread and stop the flow of time altogether or pull it so that time reverses, but this requires extreme force of will and mental fortitude.

With enough practice, a mage can also learn to separate their will from their projection, and thus can manipulate their own position on Nascindor via manipulating the projection, resulting in movement that is imperceptible to the naked eye in the real world.
Generally speaking, the Tapestry offers a mage or wizard the tools to create near limitless effects, if the practitioner has the inventiveness and mental acuity to grasp the Tapestry's full potential. The most powerful individuals have learned to modify the size of their projection in the Tapestry, allowing them to accomplish truly devastating, landscape-altering feats of magical might.

Once you're in, concentrate on staying in.

The Font will try to expel you.

–Zakiyah Farek, guildmaster of the Enlightened Few, referring to the Font of Magic

by Midjourney

_{A dramaticized depiction of projection}