• Here are a few options
• all suitable for South American Spanish
• with slight variations in nuance: **Option 1 (Most common and direct):** "**Ligeras marcas en ambas mangas y en la parte trasera inferior.**" *(Slight marks on both sleeves and on the lower back part.)* **Option 2 (Slightly more formal/precise for "faint"):** "**Tenues marcas en ambas mangas y en la parte trasera inferior.**" *(Faint/subtle marks on both sleeves and on the lower back part.)* **Option 3 (Using "espalda" for the back of the shirt):** "**Ligeras marcas en ambas mangas y en la parte baja de la espalda.**" *(Slight marks on both sleeves and on the lower part of the back.)* You can choose the one that best fits the specific context or desired tone. "Ligeras marcas" is a very safe and common choice. If the "marks" are more like stains
• you could use "ligeras manchas.

Características:

• De manga larga