Which thumb should I use for the thumb impression?

Most notices ask for the left thumb impression for all candidates. Use another thumb only if the notice allows it and follow its instructions.

Which ink colour is accepted for thumb impressions?

Blue or black stamp-pad ink is commonly specified. Check your notice for its exact wording.

My thumb impression is just a dark blob. What went wrong?

Too much ink or too much pressure. Use less ink, press gently and roll the thumb once in a single smooth motion.

Can I take a thumb impression photo with my phone?

Yes, if the light is good, the phone is parallel to the paper and the ridges are clearly visible when you zoom in.

What if my left thumb is injured or missing?

Notices usually explain what to do, often allowing the right thumb with a note or declaration. Follow your notice rather than guessing.

How to take and upload a left thumb impression

Updated 11 October 2026

Left thumb impression resizer →

Several recruitment applications, particularly for banking, railway and some state-level posts, ask for a scanned left thumb impression (LTI) along with the photo and signature. Some also check the impression again at the exam centre or during document verification, so it needs to be clear and genuine.

Which thumb?

Most notices simply ask for the left thumb impression, for all candidates. Use your left thumb unless your notice says something different. If your left thumb is missing, injured or the impression cannot be taken, notices usually describe an alternative (often the right thumb) and may require a declaration or a note on the form. Follow exactly what your notice says rather than guessing.

What you need

A stamp ink pad, preferably blue or black. Notices commonly mention these colours.
A sheet of plain white paper.
Tissue or a cloth to clean your thumb afterwards.
A scanner or a phone camera with good light.

Step 1: make a clear impression

Wash and dry your thumb. Oil, cream or sweat causes smudges.
Press your thumb gently on the ink pad, rolling slightly from one side to the other so the whole pad of the thumb is inked. Do not over-ink.
Place the thumb on the paper and roll it once, smoothly, from one side to the other, with light, even pressure. Lift straight up.
Check the impression: you should see the ridge lines clearly, not a solid blob. Make three or four impressions and choose the clearest.

Too much ink fills in the ridges and gives a dark patch. Too little gives a faint, broken print. A light first press on scrap paper often removes excess ink.

Step 2: scan or photograph it

Scanner: scan at 200 or 300 DPI, colour or greyscale, saved as JPG.

Phone: place the paper flat in good daylight. Hold the phone parallel to the paper, about 15 to 20 cm away, and tap the impression to focus. Avoid flash and shadows. Take two or three shots and pick the sharpest; ridge lines should be visible when you zoom in.

Step 3: crop and resize

Crop so the thumb impression fills most of the image with a small white border. Then resize to the dimensions and file size in your notice. Requirements vary between bodies. Pixel sizes in the low hundreds (for example around 240 × 240 px) and file sizes somewhere in the range of about 20 to 50 KB are commonly seen, but your notice is the only authority; check our exams page and the official advertisement.

Worked example

Suppose a notice asks for 240 × 240 px, 20 to 50 KB, JPG.

Step	Result
Phone photo of the paper	3000 × 4000 px, about 2.5 MB
Square crop around the impression	about 900 × 900 px
Resize to 240 × 240 px	typically 15 to 35 KB depending on paper texture
Adjust quality to land near 30 KB	safely within 20 to 50 KB

If the impression is rectangular in your notice (for example 3 × 4 cm), use the cm-to-pixel formula and crop to that shape before resizing so the print is not stretched.

Our thumb impression tool crops, cleans the background and resizes in one place, entirely in your browser.

Things that cause rejection

Smudged or blotted impression with no visible ridges.
Impression of the wrong thumb or a finger instead of the thumb.
Uploading the impression in the signature or photo field.
Very dark or very light scan where the print cannot be seen.
Stretching a rectangular crop into a square, which distorts the print.

Keep a copy

Keep the paper with your impressions and the digital file. Some recruitment processes compare your impression at later stages. Using the same careful method every time helps your prints match.

Questions people ask

Which thumb should I use for the thumb impression?: Most notices ask for the left thumb impression for all candidates. Use another thumb only if the notice allows it and follow its instructions.
Which ink colour is accepted for thumb impressions?: Blue or black stamp-pad ink is commonly specified. Check your notice for its exact wording.
My thumb impression is just a dark blob. What went wrong?: Too much ink or too much pressure. Use less ink, press gently and roll the thumb once in a single smooth motion.
Can I take a thumb impression photo with my phone?: Yes, if the light is good, the phone is parallel to the paper and the ridges are clearly visible when you zoom in.
What if my left thumb is injured or missing?: Notices usually explain what to do, often allowing the right thumb with a note or declaration. Follow your notice rather than guessing.