A signature image is one of those small files that saves a lot of printing and scanning: a letter, a quote, an internal form or an email footer can carry your signature without a trip to the printer. Done badly, though, it shows: a white rectangle over a grey signature line, a blurry scribble, or a picture that lands in Word half a page wide. This article walks through making a clean one with the signature generator, with the actual numbers it produces, and ends with the mistakes worth avoiding.
Why the file type matters
There are two common picture formats, and only one of them suits a signature.
- JPG stores every pixel as a colour. There is no "nothing here", so the space around your signature is saved as white. On a white page you will not notice; on a coloured letterhead, a shaded table cell or a grey form field you get a visible white box.
- PNG can store an alpha channel: each pixel also says how opaque it is. Pixels with no ink are fully transparent, and the soft edge of each stroke is partly transparent, so the ink blends into whatever is underneath.
That is why the tool only exports PNG. The checkerboard in its preview is the usual way of showing "transparent": the checks will not be in the file.
Step by step
- Open the tool and choose Draw or Type.
- If you draw, sign inside the pad, above the dashed line, and make the signature large: use most of the width. A mouse works, but a finger on a phone or a stylus on a tablet gives a more natural line. With a stylus that reports pressure, switch on pen pressure for thicker strokes where you press.
- If you type, enter your name and try the styles. They are handwriting fonts that ship with your operating system, so the result on Windows is not the same as on an iPhone. No font is downloaded.
- Choose the ink: black for anything that will be printed, faxed or scanned, dark blue if you want it to look signed by hand.
- Choose the resolution and margin, check the size under the preview, and download.
A worked example with real numbers
Say the pad is 600 by 200 pixels on your screen and your signature covers a box about 380 pixels wide and 120 tall. With the resolution set to 3×, every point you drew is multiplied by three, so the ink covers about 1,140 by 360 pixels. The tool then finds the outermost pixels that contain ink (anything more than barely visible), cuts the picture there, and adds the margin on every side. With a margin of 12 pixels the downloaded PNG is:
- width: 1,140 + 2 × 12 = 1,164 pixels
- height: 360 + 2 × 12 = 384 pixels
Is that enough? A printed signature is usually 4 to 6 cm wide. At 300 dots per inch, a common print resolution, 5 cm is 5 ÷ 2.54 × 300 ≈ 591 pixels. Our 1,164 pixels squeezed into 5 cm gives roughly 590 dots per inch, comfortably sharp. At 2× the same signature would be 760 + 24 = 784 pixels wide, still fine for print; 1× is only good for screens.
Putting it into Word
- Insert > Pictures, choose the PNG.
- Word sizes a picture from the resolution stored in the file, and when there is none it assumes screen resolution, so a 1,164-pixel image is treated as about 30 cm wide and usually lands filling the whole width of the page. Drag a corner (not a side, so the proportions stay) or type a width of about 4.5 cm in Picture Format > Size.
- Set Wrap Text > In Front of Text so the signature can sit on the line without pushing text around, then drag it into place.
- Save as PDF if you are sending the document out, so nobody's layout moves it.
Putting it into a PDF
Most PDF editors and readers with a "Fill & Sign" or "Add image" feature accept a PNG and keep its transparency. Place it, resize it with the aspect ratio locked, and flatten or save. If your reader only lets you draw a signature, you can often import an image as a reusable signature instead; look for "Add signature > Image".
A picture is not a digital signature
A PNG of your signature proves nothing about who placed it: anyone who receives one document can copy the image into another. A digital signature is different: it is a cryptographic seal tied to a certificate, and it shows whether the document changed after signing. Where a contract, a tax return or an e-invoice requires an electronic or digital signature, a signature image does not replace it. Use the image for the paperwork you would otherwise print, sign and scan, and treat the file like a rubber stamp: keep it in a private folder and do not post it.
Common mistakes
- Saving or converting to JPG. The background turns white. Keep the PNG; if a form insists on JPG, it will not be transparent.
- Signing small. A signature drawn in a corner of the pad has few points and looks jagged when enlarged. Sign large and shrink it in the document.
- Stretching it. Dragging a side handle in Word distorts the letters. Use a corner, or type one dimension with "lock aspect ratio" on.
- Light colours. Pale blue or grey disappears when the page is photocopied or scanned in black and white. Black or a dark blue is safer.
- A photo of a signature on paper. That keeps the paper texture and shadows. If you must start from paper, crop it tight with the image crop tool, but redrawing it in the pad usually gives a cleaner result.
- No margin. With a margin of zero, the loops touch the edge of the picture and some editors clip the anti-aliased edge. Eight to sixteen pixels is enough.
Everything above happens in your browser: the strokes, the typed name and the PNG never leave your device.