IBPS thumb impression, 20–50 KB
Press the left thumb on white paper in black or blue ink. Crop the print into a square. If you have no left thumb, the notice allows the right thumb.
A smudged or faint print fails review even when the file size is correct.
What usually goes wrong
Do not photograph the whole sheet.
What this page checks
JPEG, 240×240 pixels, 20–50 KB, the size IBPS describes at about 200 dpi for a 3 cm square.