You sign your name on a plain white sheet, photograph it with your phone, upload it, and the portal rejects it. You try again with better handwriting. It still gets rejected. The signature was never the problem.

What your phone camera does to white paper

Look closely at the photo you took. That paper is not white. It is light grey, or slightly yellow, or beige, with a shadow gradient down one side where your hand or your head blocked the light. Your eye corrects for all of this automatically and reads it as "a white page". A camera records what is actually there, and what is actually there is a mid-grey rectangle with some dark marks on it.

Application portals expect a signature on a clean background, and some of them measure it. A photographed signature is also usually far larger in file size than a scan for the same amount of ink, because all that smooth grey noise costs data - which is why the same file often fails a 10-20 KB signature limit as well.

Cleaning it up

The fix is not to brighten the whole picture, which just turns grey paper into lighter grey paper and washes out your ink at the same time. What you need is to separate the ink from the paper and put the ink back on a genuinely clean background.

1. Open the Signature Cleanup tool and drop in your photo or scan.
2. Look at the before and after panels side by side. The "after" panel updates as you adjust things, so you can see exactly what you are about to download.
3. Move the strength slider if the default is not right. Slide right if parts of your signature are disappearing; slide left if specks of paper texture are showing up as dots around it.
4. Choose your background: solid white for a form upload, or transparent if you are going to place the signature on top of a document.
5. Leave "trim the empty paper around the signature" ticked. This is more important than it looks - see below.
6. Clean it up and download.

White or transparent?

Choose white for almost every form. Exam and government portals expect an ordinary JPEG on a plain background, and a fair number of them reject PNG files outright. A transparent PNG that looks perfect on your screen can be refused at upload for the format alone.

Choose transparent when the signature is going on top of something else - a contract, a letter, a PDF form - so that no white rectangle sits over the text or the signature line underneath. That is the version to use with the Sign PDF tool, and it is worth saving one good transparent copy so you never have to redo this.

Why trimming the paper matters so much

Most exam forms want a signature in a 4:1 aspect ratio - four times wider than it is tall. A signature photographed in the middle of an A4 sheet is roughly 3:4, which is the opposite shape. Even if the size in kilobytes is right, the shape is wrong, and some portals check the shape first.

Trimming away the blank paper leaves a tight box around the ink, which is naturally close to that wide shape. It also means that when you resize the file afterwards, the pixels are being spent on your actual signature rather than on empty margins.

Getting a better photograph in the first place

No amount of processing beats a decent source image. Thirty seconds of care here saves a lot of fiddling later.

• Plain white paper, unlined. Lined paper is genuinely hard to clean up because the ruling is ink too, and the tool cannot reliably tell your pen from the printed line.
• Black or blue ink, and a pen that actually flows. Pencil, gel pens in light colours and dying ballpoints all sit close to the paper in brightness, which makes the separation harder and is often against the form's rules anyway.
• Even light, no shadow. Near a window on an overcast day is close to ideal. Direct overhead light with you leaning over the page is the worst case.
• Straight on, not at an angle. Hold the phone parallel to the paper so the signature is not skewed or keystoned.
• Sign large. A big signature on the page gives more pixels of ink to work with, and it scales down cleanly. A tiny signature scaled up never looks right.

What comes next

A cleaned-up signature is the input, not the finished upload. Once you have it, resize it to your exam's actual specification with the Exam Photo and Signature Resizer - it knows the published size and shape for SSC, IBPS, RRB, UPSC and others, and lands the file inside the required range rather than just under the ceiling. There is a shortcut button straight to it from the cleanup result, and the resizer offers the same background cleanup inline if you would rather do both in one pass.

If a portal has already refused your file and you cannot tell why, the Form Upload Checker will tell you which specific requirement it fails.

A note on where the file goes

Nowhere. The cleanup runs entirely in your own browser - your signature is not uploaded to us, and a signature image is exactly the kind of thing you should be careful about handing to a website. Keep the same caution with the finished file: it is a usable copy of your handwriting, so store it where you would store a scan of your ID, not in a shared folder or a group chat.