How to make a clean thumb impression image for online forms

• Use a stamp pad with blue or black ink, not a pen.
• Press the thumb on the pad, then roll it once from one side to the other on plain white paper.
• Make three or four impressions and pick the clearest, with visible ridges and no smudge.
• Use the thumb the form asks for; many specify the left thumb.

1. 1Photograph the impression in daylight from directly above.
2. 2Open Thumbmark maker, choose the photo, pick the ink colour and adjust the strength until ridges are clear.
3. 3Download the result, then crop it to a square with Crop image.
4. 4Open Resize image, set the size from the form (such as 240 × 240 pixels), turn on Limit the file size and enter the maximum (such as 50 KB).
5. 5Check the file is above the form's minimum size.

Thumbmark maker gives a transparent PNG. Most exam forms want a JPG on white: convert it with Convert image, choosing JPG and white as the fill colour for transparent areas, before resizing.

Some forms want a scan of a physical impression on paper rather than a photo, and a few want both hands' fingers and thumbs in one image (NEET UG, for example). Follow the notification. For the full IBPS set of files, see IBPS photo, signature, thumb impression and declaration sizes.