New Spell: Christensen's Connected Canvas (PEACH!)

[Isocahedron]

3rd-level evocation

Casting time: 1 minute
Range: Touch
Components: V, S, M (a piece of chalk, which the spell consumes)
Duration: Concentration, up to 1 hour

You connect a flat, blank surface to a connected canvas which has a sigil sequence you know. As you cast the spell, everything written on the canvas to which you are connecting becomes written on the target surface. Anything you write on the surface will be written on the connected canvas, and anything you erase may also be erased (see below). If you attempt to connect to a canvas to which someone else is already connected, the spell fails but the casting is not wasted.

You may also use this spell to create a connected canvas. When you target a surface, you do not connect it to anything, but instead spend the full duration focusing the spell. You may create multiple sigil sequences, and specify whether someone connecting using a given sequence is allowed to erase things written by others (or only themselves), and which sections of the canvas they may write on. A connected canvas may be at most 5 square feet in size. If you cast this spell on the same surface every day for a year, the canvas becomes permanent. You may still cast the spell again to add, remove, or alter the permissions of sigil sequences.

At Higher Levels. When you cast this spell using a spell slot of fourth level or higher, you may connect to or create one additional canvas for each slot level above 3rd.

Spell Lists. Bard, Sorcerer, Warlock, Wizard

[JNAProductions]

Like Sending, but lasts longer and can therefore be used to send much longer messages. Also pictures.
Unlike Sending, it requires more prep work and time to cast.

I think it might be best to require the receiving canvas to be in a set place. You can send to it using any ol' blank surface, but to receive needs something more elaborate. I'd also almost certainly add an expensive material cost to the creation of a sigil-enabled canvas.

[Isocahedron]

I think it might be best to require the receiving canvas to be in a set place. You can send to it using any ol' blank surface, but to receive needs something more elaborate. I'd also almost certainly add an expensive material cost to the creation of a sigil-enabled canvas.

Ah. Set-place was my intention, but I suppose RAW you could make a canvas out of a large roll of parchment or something, and then carry it around. Not sure if that creates any broken interactions, though -- maybe I should allow it? It would let an adventuring party carry one around for their mobile base, but I don't see how that's a problem.

As for costly material components: yeah, I can see that. Maybe in that case it shouldn't have a year-casting requirement, and instead becomes instantly permanent when you spend the diamond dust / copper rod / whatever.

[JNAProductions]

Ah. Set-place was my intention, but I suppose RAW you could make a canvas out of a large roll of parchment or something, and then carry it around. Not sure if that creates any broken interactions, though -- maybe I should allow it? It would let an adventuring party carry one around for their mobile base, but I don't see how that's a problem.

As for costly material components: yeah, I can see that. Maybe in that case it shouldn't have a year-casting requirement, and instead becomes instantly permanent when you spend the diamond dust / copper rod / whatever.

My idea, and it's your spell so disregard if you want, is that you have a canvas that receives. This has to be anointed with special inks, or metals, or whatever expensive component is required. This canvas is largely immovable-it could be built into a ship, for instance, but it won't fit in a backpack without destroying the symbols and runes.
But you can use much smaller and more easily portable canvases to link BACK to that canvas. Carry around a sketchpad (anachronistic, but the point is there) and for a 3rd level slot and a minute of casting, you get to link it to the bigger one for an hour.

And yeah, material component should be fine to have it happen sooner than a year. Maybe require casting it for a week straight? But not super long.