While I don't think it's completely impossible, it's certainly impractical for a few reasons.
Firstly, the magical inks used to empower arcanist grimoires use metallic bases such as gold and electrum that conduct the flow of aether which, if we follow standard real world logic, would be highly toxic to embed in the skin. What that means isn't that the spell wouldn't work, just that the spell in question wouldn't be able to be enhanced by the ink that is used. You could use ordinary plant-based ink to tattoo the design onto a body, but it would be fairly weak since it lacks the amplification of the inks.Â
Secondly, the designs in arcanist grimoires are more like cheat sheets than anything else. They're one part reference, two parts program so that the arcanist can easily draw the geometry in their head to focus and shape their aether into a spell, because otherwise the geometries are very complex and ostensibly difficult to memorize. If you were to put one of these designs on your body, you would have to place them somewhere that is easy for you to see in order to reference the spell and form the geometry in your head. Having one of these tattoos on your back, for example, would be completely pointless because you wouldn't be able to see the design and thus won't be able to visualize it in a reasonable amount of time.
With all of that said, like I stated above, it's not impossible. You could put a geometry for a small spell on the back of your hand, for example. So long as you manage to accurately capture the details of the geometries, you could use it to fire off a few weak spells without the need for a grimoire. It'd also be possible to place a geometry on your forearm, so long as you drew it in a way that you could visualize the design accurately enough for the spell to work.
Also, it's suggested that grimoires themselves in addition to the inks used to draw the designs amplify arcane magic, so without metallic inks or the grimoires, a user would have to pour a great deal of their personal aether into the spell in order to make it reasonably powerful. A normal arcanist draws from their store of aether--their MP, basically--and visualizes the design from a reference within the grimoire. The designs within grimoire and the metallic inks used to draw that design shape the aether into the desired spell amplify the effect of the spell as it is cast. An arcanist using tattoos would lack the enhancement of the grimoire, so it'd be pretty draining even for simple spells.
So with all of that in mind, it's not impossible or implausible, but it is a bit impractical. An arcanist spell prepared in this manner with body tattoos would be more of an emergency measure or backup weapon than anything else, like a pocket pistol or derringer.
Firstly, the magical inks used to empower arcanist grimoires use metallic bases such as gold and electrum that conduct the flow of aether which, if we follow standard real world logic, would be highly toxic to embed in the skin. What that means isn't that the spell wouldn't work, just that the spell in question wouldn't be able to be enhanced by the ink that is used. You could use ordinary plant-based ink to tattoo the design onto a body, but it would be fairly weak since it lacks the amplification of the inks.Â
Secondly, the designs in arcanist grimoires are more like cheat sheets than anything else. They're one part reference, two parts program so that the arcanist can easily draw the geometry in their head to focus and shape their aether into a spell, because otherwise the geometries are very complex and ostensibly difficult to memorize. If you were to put one of these designs on your body, you would have to place them somewhere that is easy for you to see in order to reference the spell and form the geometry in your head. Having one of these tattoos on your back, for example, would be completely pointless because you wouldn't be able to see the design and thus won't be able to visualize it in a reasonable amount of time.
With all of that said, like I stated above, it's not impossible. You could put a geometry for a small spell on the back of your hand, for example. So long as you manage to accurately capture the details of the geometries, you could use it to fire off a few weak spells without the need for a grimoire. It'd also be possible to place a geometry on your forearm, so long as you drew it in a way that you could visualize the design accurately enough for the spell to work.
Also, it's suggested that grimoires themselves in addition to the inks used to draw the designs amplify arcane magic, so without metallic inks or the grimoires, a user would have to pour a great deal of their personal aether into the spell in order to make it reasonably powerful. A normal arcanist draws from their store of aether--their MP, basically--and visualizes the design from a reference within the grimoire. The designs within grimoire and the metallic inks used to draw that design shape the aether into the desired spell amplify the effect of the spell as it is cast. An arcanist using tattoos would lack the enhancement of the grimoire, so it'd be pretty draining even for simple spells.
So with all of that in mind, it's not impossible or implausible, but it is a bit impractical. An arcanist spell prepared in this manner with body tattoos would be more of an emergency measure or backup weapon than anything else, like a pocket pistol or derringer.
