How To Insert Your Signature In Your CAD Drawings

Updated Feb 2, 2020
signature, Scan2CAD logo

A big portion of the userbase for most CAD software are architects, designers, and engineers. For most of these users, CAD software is extensively used to draft up floor plans and technical drawings. In a lot of these cases, these drawings will have signatures or professional seals to comply with title block regulations or standards.

Drafts might resort to taking scanned copies of the signature and then import these into the drawings. Now, this poses a lot of issues, including the pixelated looks of most scanned images inserted into CAD drawings and the usability of CAD files that contain inserted raster images. The better but more tedious option would be to trace these signatures to create vectorized linework versions of them.

For those of us that don’t have the time to manually trace and convert scans of signatures, there are automatic alternatives that have a leg up on both labor and time, the most reliable of which is Scan2CAD. In this article, we’ll discuss the process of inserting your signature into CAD drawings without having to resort to manually tracing them on your CAD program.

Video tutorial: Converting your signature for CAD

In the following video, we demonstrate how to convert an image of your signature to a CAD format using Scan2CAD.

View video transcript

Hey there. So today we’ll be taking a look at how we can use Scan2CAD to convert scanned copies of our signature into vector images that we can use in our preferred CAD software. So the most important thing with any CAD, or conversion software rather, is the quality of the source image. So ideally we want something that looks like this, clean and crisp as much as possible, no blurriness or pixelations, and we want to avoid any creases or shadows that would come with less than ideal pieces of paper that we scan in our scanners.

So once we get something that we wanna convert, the first step would be to click on “Clean image” over here. Click on “Threshold” if it’s not already greyed out, this just converts the entire image into a black and white image. Click on “Remove speckles and holes. We can mess with the sliders here if we want to, but I’m just gonna keep them at the default position. And next would be to click on “Smooth”. So this should be okay. Next step would be to click on “Convert image”. Now, there are two options when we try to convert signature scans; it would be “outlined” and “solid”. Let me just show you what these two do.

So first off is solid. Actually, let’s untick this one since it’s not really needed here. We don’t need circles there. So as you can see, if we click on “solid”, you’re gonna get something that looks like this; solid and black vector objects. At first, I think you’re gonna want to use these, but I’ll show you the difference between outlines. So if we click on “outline” and click “run”, we’re gonna get something that looks like this. So it kind of creases around the black parts of the signature. So when we use solid… Just wanna show you why you might not want to use this for your CAD software. Click on “OK”.

It seems like it’s a solid black object, but actually it’s a black object with white objects overlaid on top. See, you can even delete these ones. Click on the eraser tool and just click on these ones. And I got left with the solid black object under the white overlays. This is just the way that Scan2CAD converts objects like these ones. There isn’t really a way around it, it just makes the technical process of it more efficient and it makes the conversion go a lot smoother.

So technically, if you do import this into your CAD software, it’s gonna be effectively the same. But if there’s something that you wanna do… Let’s just close up the vector files, I’ll show you what else we can do. The option of using outlines still remains, so let’s click on “run”. Actually, let’s untick that. And then if we’re happy with the preview over here, we click on “OK”. Sorry, “Run,” and then “OK”, and now it looks like this. So what I would do if I didn’t want something similar to the last one is to export this file, and then when we put it into our CAD software, all I do is just fill in the inside of this outline with a solid fill, and that should be good enough to create sort of a solid signature that we can use on our CAD software.

So basically, those are the two options. You’ll essentially be getting the same result with either one, but it just depends on your preference. Whichever you did pick, the last step is the same, just click on “File”, “Save as,” Vector”, and just pick whatever format it is that you wanna use. So in our case, let’s go with the latest DWG format, and whatever it is. In this case, it’s a signature over here. Then you just click on “Save.” So it’s as simple as that. As you can see, you can choose to tick or untick this, it just converts to black vectors in the images to white.

This is suitable since a lot of CAD software actually have black background. So if we have black vectors that we put them against a black background of CAD, then they’re not really visible. So it depends on what you want to do with the images. Let’s tick on “Default”, so let’s keep it ticked there and click on “OK.” So that’s the whole process and it’s as simple as that. Alright, hope this helps.


Full instructions

1. Getting the right source image

Frank Sinatra signature

Pick something high-quality

With any conversion process, the number one most important factor in getting high-quality output is the initial quality of your source image. With scanned copies of a signature, make sure that the hard copy was scanned at 300-600 DPI. With low DPI scan settings, you risk getting a signature that would be too pixelated to accurately vectorize.

Aside from the scan settings, make sure to also take the time to check for any unwanted marks, smudges, or creases on the paper you’re scanning. As much as possible, you want nothing but the signature visible on the paper you’re planning to scan.

In short, just take the time to make sure you have a good initial copy – something you wouldn’t mind putting on official documents. You’re only going to get something as good as you put in.

2. Cleaning the raster image

raster editing screenshot

Cleaning up

After opening up the chosen source image on Scan2CAD, we’ll have to do a few more tweaks to optimize it for conversion. Every individual signature is different, but the basics of cleaning up any scanned image you’re looking to convert are – black and white, de-speckle, and smooth.

For an efficient and clean conversion, black and white images are preferred by the software. Even when you’ve scanned a visually black and white image, the scanner will still tend to pick up the tiniest hints of gray tones and other colors all over the paper, so always make sure to tick the ‘Threshold (Black & White)’ box if it can be ticked.

And just to cover our bases in case the original source image wasn’t quite clean yet, try to tick ‘Remove Speckles & Holes’ as well as ‘Smooth’ just to make the raster image that much crisper and cleaner.

Do note that if these tools still don’t cut it, you can manually erase and add drawing elements onto the raster image with the editing tools at the left of the Scan2CAD interface.

 3. Conversion settings

raster conversion screenshot

Tweaking the conversion settings

There are a couple of settings you can play around with when converting your raster signature. Among the three available Vectorization Methods, you’re going to want to try Outline and Solid. Both will produce results you can effectively use in your CAD program, but we’ll go over their specific attributes in the next steps.

The Vector definition slider is something you’ll want to adjust. The lower the value, the “sharper” the vector output. That is, it’s going to be more similar to the original raster image. The higher the value, the “smoother” the image. So depending on the quality of the original source image, you’ll want to find the sweet spot. Clicking on the Run button will show you a preview of the converted image.

For the rest of the conversion options, try to untick “Identify Circles” since there are not identifiable perfect circles in most signatures and then you can leave the rest of the options as is.

4. Converting to Solid

convert to solid screenshot

White fill overlays on top of black fills


The enclosed or partially enclosed negative space in written down letters are called counters. So imagine the letter O as a black circle and its counter as a round hole that was cut out of it.

Now, the reason we’re giving you the proper term for that enclosed negative space is so that you understand when we say that Scan2CAD doesn’t technically recognize these counters or negative spaces as cut-outs. Rather, what Scan2CAD does is it recognizes these counters as white solids and then puts those white solids on top of black solids.

Imagine the O from earlier except instead of cutting out the counter in the middle, you put another solid circle, this time white, on top of the black circle.

There are some technical reasons for letter Scan2CAD to do that, but suffice to say it makes the conversion process smoother and simpler.

This has essentially the same output as the Outline option of conversion, provided you opt not to convert all black vector objects into white ones while saving (more on that shortly). But if this isn’t what you were looking for, let’s try out the other vectorization method.

5. Converting to outline

signature outline screenshot

Outline vector

As the name implies, choosing the outline option simply creates a vector outline around the black parts of the signature.

Although this might not look complete now, what you can opt to do is export this into your CAD software and then proceed to fill out the insides of the outline with a solid hatch. It’s a relatively fast process and you don’t need to worry about solid overlays anywhere.

6. Final edits

As with the original raster image, you can manually edit the produced vector objects manually with the tools on the left side of the Scan2CAD interface.

Do note that these are meant for minor rectifications, mostly to erase any stray speckles anywhere in the image.

If you prefer, you can also use the scale tool to try and set an initial size for the produced vector image. But you would probably have an easier time doing that in your preferred CAD program afterward.

7. Saving

saving the vector file screenshot

Saving the vector file

After all the edits have been made, the last part would be to save the newly converted vector file. At this point, you can choose the DXF and DWG file formats and save it under its appropriate file name. But you can also save the vector file to any popular vector format such as G-code formats including .CNC , .NC and .TAP.

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