Prior to executing the ink test  , the lesion should be evaluated clinically and dermoscopically. Once this has been accomplished, liquid ink (ie, from a fountain pen) should be applied directly onto the lesion. The ink should be left on the skin for a few seconds to allow it to penetrate the furrows. The excess ink should then be wiped off using a cotton swab. The ink will at first diffusely color the entire skin surface. The subsequent cotton swab wiping will only remove the ink on the skin on the surface (ie. Ridges). The furrows or other structures will retain the stain and become clearly visible on dermoscopic examination as thin inked lines. This will make it easy to evaluate whether the melanin pigmentation follows the ink lines (ie, parallel furrow pattern) or if the pig- mentation is located in between these ink lines, thus representing a parallel ridge pattern. Another interesting observation made by us was that initial vigorous rubbing of the skin with alcohol pads followed by the application of ink results in the accentuation of the eccrine pores by ink, thereby making it easy to identify the ridge. We theorize that the vigorous rubbing of the skin with alcohol results in the removal of keratin from around the eccrine pores and furrows. This results in less ink adhering to the furrow, while allowing the ink to enter the openings of eccrine pores. The ink test can as well be used for the in vivo staining of comedo-like openings or fissures and ridges revealing the 3 dimansional aspect in seborrheic keratoses .
- Braun et al.: The furrow ink test: a clue for the dermoscopic diagnosis of acral melanoma vs nevus. Arch Dermatol 2008;144:1618-20. PMID: 19075144. DOI.
- Yagerman & Marghoob: The ink test: identifying 3-dimensional features of seborrheic keratoses under dermoscopy. JAMA Dermatol 2013;149:497-8. PMID: 23715284. DOI.