Sign Documents without Paper

When a document requires a signature, it’s natural to assume that it requires ink on paper. And sometimes it does, but in a great many situations, you can “sign” and electronically deliver a document, whether you originally received it in digital or physical form.

In this chapter I begin by talking about situations in which the recipient needs to see your handwritten signature. For many contracts, legal agreements, and other day-to-day business documents, you can substitute a scanned copy of your signature. Likewise, it’s possible to collect someone else’s handwritten signature on the go, typically using an iPad or other mobile device.

There’s also another concept you should be aware of—a digital signature, which is a way of certifying that you, and you alone, are the sender of a message or the signatory of a document. I cover this sort of signature briefly toward the end of the chapter.

Determine When a Pseudo-signature Is Acceptable

When someone asks you to sign a document, simply ask this question:

Can I return this by fax or email, or is an original signature required?

You’d be surprised how often electronic transmission of a signature is considered perfectly valid. I’ve done this countless times myself—for example, when returning contracts for writing magazine articles and doing technical reviews for new books. If the other party is content with fax or email, I’m only happy to oblige. (And, as I explain shortly, you can send a fax by email, so it amounts to the same thing.) In cases where only an original signature is accepted, I send a piece of paper, but in my recent experience that happens mainly in cases where the thing to be signed is of tremendous gravity (or a lot of money is involved). You’ll probably need ink on paper for a lease, bank loan, or affidavit, but for run-of-the-mill contracts and agreements, an electronic signature should suffice.

I’ve heard that some financial institutions use software that flags signatures on faxes that appear to have been added digitally. Although I have no technical information on how this works and don’t know which institutions use such a system, be aware that in rare cases you might get a phone call asking you to confirm a signature—even when the recipient accepts a fax.

Scan Your Signature

To be able to fax or email signed documents without generating more paper, the first thing you need is a good digital copy of your signature. To make one, follow these steps:

1. On a clean, white, unlined sheet of paper, sign your name in dark ink at a normal size. If your signature takes on multiple forms, put them all on the paper. For example, sometimes I sign my name “Joe Kissell,” sometimes “Joseph Kissell,” and sometimes “Joseph W. Kissell,” depending on the context.
2. Scan the page with your signature. If your scanner is normally set to reduce the resolutions of scans, bump it back up for this one—600 dpi is a good choice. And, even if you sign your name in black ink, do the scan in color. These extra tweaks will improve the quality of your scanned signature, which will in turn increase its perceived authenticity and the flexibility you have in using it later.
3. In your favorite image editing program (such as Preview, Photoshop Elements, or GraphicConverter), open the scanned image, crop it so that only a few pixels of white appear around the outside, and confirm that the white truly is white. (If it’s gray, or speckled, or otherwise “noisy,” adjust the contrast or brightness, or use whatever other tools your image editor provides to eliminate the noise.)
4. Optional: If you have the image editing kung fu to make the background of your signature transparent, do so (sorry, it’s too involved to explain here); this lets elements of the original PDF, such as a signature line, show through the background.

   Tip: If you have PDFpen (or PDFpenPro), you need not bother with creating a transparent background, because PDFpen has a built-in command to make your signature’s background transparent when you add it to a PDF. Competing tools don’t have this capability, so transparency comes in handy in those tools.

5. Save the file in either TIFF or PNG format (your choice, but PNG files tend to be smaller).

You now have a graphic file (or perhaps more than one) consisting only of your signature, with either a white or transparent background. Make sure you keep this in a convenient location. (If you use an iOS device, you’ll want to keep it there as well as on your Mac, so that you can “sign” documents on the go with a mobile version of PDFpen too!)

Superimpose Your Signature on a PDF

Now comes the fun part: you open the PDF of the document to be signed, overlay the image of your signature, and save the composite image as a new file, which looks like you physically signed it.

I know of several tools offhand that can pull off this trick on a Mac, and two of them are even free. But in my experience, PDFpen does a much better job than the rest, so that’s the one I recommend. (PDFpenPro has the same capability.) As a result, I’m going to provide complete directions for doing this with PDFpen, but only cursory instructions for doing it with a few other tools.

Add a Signature with PDFpen

To add your scanned signature to a document using PDFpen, follow these steps:

1. Open the PDF needing a signature in PDFpen.
2. Choose File > Insert (or click the Insert button on toolbar), navigate to the scanned image of your signature you created earlier, and click Open. PDFpen places your signature on the page.
3. Drag your signature to the desired location on the page and, if necessary, resize it by holding down the Shift key while dragging one of its corners.
4. If your signature doesn’t already have a transparent background, select it and choose Edit > Make Transparent Image. In the dialog that appears, click once in the white space surrounding your signature, and then click Make Transparent.
5. Save and close the document (or, if you prefer, hold down the Option key and use File > Save As to save a copy with your signature, keeping the original intact).

You can now attach the signed PDF document to an email message. If only fax is acceptable, no problem—you can use any of the email-to-fax gateways described in the next chapter (Fax without Paper) to send a fax without a fax machine.

Store Your Signature in PDFpen for Easy Access

If you’ll be adding your signature to PDFs frequently in PDFpen, you may want to add your signature to the PDFpen library. To do so, place your signature in a PDF as in Steps 1–4 just previously, and make sure the signature image is selected. Then, click the Library button on the toolbar. In the Library window, from the Add pop-up menu at the lower left, choose Add Selected Imprint.

PDFpen adds your graphic, including transparency, to the Custom portion of the library. Next time you want to insert your signature in a PDF, simply click the Library button on the PDFpen toolbar, click the Custom button, and then double-click your signature.

Add a Signature with Preview

If you have Mac OS X 10.7 Lion or later and a Mac or monitor with a built-in camera, you can use Preview (in /Applications) to add an image of your signature to a PDF—no scanner required! Follow these steps:

1. Sign your name on a plain piece of white paper.
2. Choose Preview > Preferences, and click Signatures.
3. Click Create Signature.
4. Hold the paper in front of your camera, and align it so the signature rests on the blue line. Click Accept to add the signature to Preview’s list. (To add more signatures, click the plus button and repeat this step.)
5. Open the PDF you want to sign in Preview.
6. If the Edit Toolbar toolbar isn’t already visible, choose View > Show Edit Toolbar (called the Annotations Toolbar prior to 10.8 Mountain Lion).
7. From the Signature pop-up menu on the Edit toolbar, choose the signature that you want to insert.
8. Click and drag to place the signature; you can then move or resize it as needed.

You can then save the PDF, and email it or fax it.

Add a Signature with Acrobat Pro

Acrobat Pro has two different methods of affixing the image of a signature to a PDF. One of them is as part of a digital signature, which I describe in a moment (see Learn about Digital Signatures, later in this chapter). The other, simpler method uses something Acrobat calls a stamp, which can be any graphic that’s overlaid on a PDF.

The basic method is to create one or more signature stamps by choosing Tools > Comment & Markup > Stamps > Create Custom Stamp and adding an image of your signature. These stamps can then be reused whenever you need them. Having configured a stamp, choose Tools > Comment & Markup > Stamps > Category Name > Stamp Name, and click to place the image at the desired spot.

Add a Signature with FormulatePro

FormulatePro, unlike the other tools mentioned in this section, is completely free. It also offers the easiest way to add an image of your signature to a PDF. After you’ve opened a PDF in the app, just choose File > Place Image, navigate to your image, click Open, and then move the graphic to the desired location.

Sign without Scanning

Even though you probably have a scanner on your desk, you may not always have it with you when you want to sign a PDF (or get the signature of someone else who may not have a scanner). Several scanner-less methods of signing PDFs exist. For example:

• Mac: If you have a Mac notebook with a multi-touch trackpad, a Magic Trackpad, or a Wacom graphics tablet, an application called Autograph lets you sign a PDF by writing (with your fingertip or a stylus) on your trackpad or tablet.
• iOS: iPad users can get similar capabilities using apps like DocuSign, SignEasy, and Sign Docs. FileMaker Go also offers digital signature capture.
• Browser: Anyone with a Web browser can sign a PDF by writing their signature with a mouse or other pointing device using a Web app called SignNow. The basic service is free; various paid levels add extra features.

Digital Forgeries

When you superimpose an image of your signature on a PDF, this only gives the appearance of a genuine signature. It wouldn’t be accepted for documents of great importance because it’s easy to fake. All anyone has to do is scan your signature (from, say, a credit card receipt or a hotel register) and they could “sign” something as you. So, let’s be clear: this is not a high-security option.

But there’s another way of signing electronic documents that is quite secure—that’s a digital signature, which I discuss next.

Learn about Digital Signatures

If your work requires you to send or receive signed legal documents of significant gravity, the sort of pseudo-signatures I’ve talked about so far in this chapter won’t cut it, because they’re too easy to fake. However, it is possible to prevent forgeries and “sign” digital documents in a way that is, in fact, much more secure even than using a pen. A digital signature does just that.

When you digitally sign a document, you embed in it information about yourself (such as your name and email address)—and possibly a graphic representing your handwritten signature. But this isn’t mere ornamentation; you’re adding a specially encrypted certificate (sometimes called a digital ID) that the recipient can validate to confirm that the signature truly is yours. The software you use to sign a document does something else, too: it calculates a unique value based on the contents of the document, and it includes an encrypted copy of that value in the signature. The result is that if the document were altered in even the tiniest way, this value would no longer be accurate, and the recipient would know that the document had been tampered with.

So, tamper-proof digital documents that can be reliably connected with a signatory sound great—there’s got to be a catch, right? Yep. In fact, there are several:

• Multiple mutually incompatible standards exist for digitally signing documents. Unless all parties involved use the same system, the process won’t work.
• Very few Mac OS X applications can digitally sign PDF documents, which are of primary concern in this ebook. Acrobat Pro can, and so can PDF Studio Pro, but if you open a signed PDF in an application, such as Preview, that doesn’t know about digital signatures, you’ll simply see an ordinary PDF.
• A certificate that can be used to verify your identity is expensive and awkward to obtain (unless you work for a large corporation or government entity that can supply its own). You can easily create your own “self-signed” certificate for free, but since no trusted third party has validated its authenticity, this is essentially no more secure than using a simple image of your signature. The recipient can verify only that the document hasn’t been tampered with, but not that you are who you say you are. (You can also obtain a free certificate that can at least confirm that your email address is the one used to request the certificate, but if you want anything fancier than that, you have to pay.)

Tip: If you have a digital certificate suitable for signing email messages, as I discuss in Take Control of Apple Mail, you can use that same certificate to sign PDFs, too. Acrobat Pro can also access these certificates in your Keychain directly.

For all these reasons, and because the details of dealing with certificates, validating signatures, and managing all the associated software infrastructure gets rather messy, I don’t include complete instructions here. (If there’s sufficient public interest, I’ll consider adding it to a future edition of this ebook.)

I can, however, direct you to two Macworld articles by Pariah S. Burke that cover portions of the process and will at least get you started:

• Create a digital ID with Adobe Acrobat explains how to create a (self-signed) digital ID in Acrobat Pro that you can use to sign documents, although it doesn’t cover the process of obtaining an externally validated certificate.
• Sign electronic documents with your own handwritten signature shows you how to add a scanned image of your signature to a digital ID and use that to digitally sign a PDF.

Adobe’s EchoSign software can also provide legally enforceable electronic signatures.