Darth Talon receiving her tattoos trough Lightning
Many Sith over time have sported interesting facial and body tattoos. These include the more common Warrior and Acolytes, as well as the fearsome Sith Lords. Notable exponents included Darth Maul, Count Dooku’s padawan Shaaleta Doneeta, Uthar Wynn, Jerec, Darth Talon, Darth Maladi, and others.
The methods of tattoo inscription vary from Master to Master. In most cases, the right to bear the marks was earned in combat by the learner and inscribed by the Master. Various methods were used. These included venomous slugs, needles, Force Lightning, acids, chemicals, dyes, lasers, and more.
Darth Maul had his applied by Lord Sidious. Needles were placed in his body as he hung from chains. Sidious indicated that the pain would “Clear his mind.” It is probable that these needles were meant to channel his neural energy in a manner similar to acupuncture.
Darth Maul receiving his tattoos trough Chemicals
From the Legacy series, Darth Talon bore extensive Sith tattoos across her entire body. Darth Krayt’s holocron clearly shows her in agony as he literally burnt them into her skin using Force lightning. She had earned the right to bear them by facing her master in single combat.
From a Sith Alchemy perspective, these tattoos may have contained Force-enhanced chemicals. It was certain that the process was agonizing, and mastery of the Force as well as more vulgar chemical means may have been employed to resist the pain. Orbalisk venom was almost certainly employed by Sidious, as the Sith Lord had access to the full range of Sith alchemical techniques.
It has been rumored that the marks may have contained vile boons in and of themselves. These could be of many natures, such as healing, strength enhancement, or other unknown uses. Bearing them was a mark of the skill of the Master, and of the learner’s resilience and full embrace of the Power of the Dark Side.