UPSC signature, 20–300 KB
Sign three times, one below the other, in black ink on white paper. Crop that block, not a single tiny signature.
One signature is not the UPSC pattern described in recent form guidance.
What usually goes wrong
If the ink is faint, the file drops under 20 KB. Use a darker pen and fill the frame.
What this page checks
JPEG between 20 KB and 300 KB. The export starts at 500×700 pixels so three lines fit. Check the current OTR instruction.