Since the last release, applying visual effects to items involves the new toolbox abilities players can activate via the Forgesmith's tools quickitem.
Here are the abilities related to VFX :
As you can the, those are modal abilities, meaning the tools require a main ability to be enabled first. Modifications are immediately applied using this tool, meaning simply deactivating the ability (via the first button, here) is enough. These modification are entirely free and do not affect the item statistics.

Until a proper guide is written, please watch the example video available above. Although it's not shown on this video, players can also remove current VFX using this tool. A weapon with a fire damage bonus on successful hits, for instance, usually have a flaming VFX applied ; but that VFX could be removed with that toolbox ability. (doesn't work on properties inherited from runes)

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