Short answer:

• Digambara tradition: Tirthankaras are naked after dīkṣā (renunciation).
• Śvetāmbara tradition: Tirthankaras may wear simple clothes for a period after renunciation, and some depictions of Tirthankaras show them clothed.

Explanation (in brief):

• Digambaras hold that the perfect renouncer becomes sky-clad (nagna) and remains naked as a sign of complete non-attachment.
• Śvetāmbaras allow clothes for lay-level renunciation steps, and scriptural accounts mention Mahāviira wore clothes for about a year and a month after renunciation before going naked; later images in this tradition can be shown clothed or unclothed depending on the context. This reflects the two traditions’ different interpretations of how strictly clothing is avoided for liberation.

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