Screenshot of a digital pattern making workspace in Adobe Illustrator showing outlines of dress pattern pieces with labeled dimensions.

Master the Art of Adding Seam Allowance to Patterns in Adobe Illustrator

Pattern Making Course in Adobe Illustrator

When it comes to Pattern Making in Adobe Illustrator, you’ve certainly leveled up your skills. You’ve crafted intricate patterns, experimented with fresh necklines, and mastered dart manipulation. But now, it’s time to embrace the next essential step: Adding Seam Allowance to Your Patterns in Adobe Illustrator! Traditionally, this task could turn into an arduous affair with a pencil and Pattern Master, especially for complex patterns with elaborate curves and numerous panels. Yet, the beauty of Illustrator lies in its efficiency – adding seam allowance becomes a swift and error-free process.

Our Pattern Making Course unlocks the method to add seam allowances in mere moments:


Tutorial Overview:

1. Use the Direct Selection tool to pick the pattern piece’s outlines. Select one line, then with the Shift key pressed, include the next, until all outlines are chosen.

2. Navigate to ‘Object’ on the top menu, choose ‘Path’, then ‘Offset Path’. Input your desired seam allowance—commonly 1cm—and hit ‘OK’. Instantly, your pattern adapts with the new seam allowance.

3. Highlight the new seam allowances and in the right toolbar, select ‘Stroke’. Assign a 2pt stroke to make these lines distinct from the pattern.

Done! Your pattern is now upgraded and ready for the next stage of our Pattern Making Course in Adobe Illustrator.

Essentials for Following Along

Before we dive in, you’ll need a bodice basic block to keep up with this pattern-making project. We offer two types of basic blocks for your selection. Standardized basic blocks are ready for immediate use, allowing you to start drafting right away, though they might not match your measurements perfectly. On the other hand, a bespoke basic block, tailored to your specific measurements, offers a precise fit but requires time to create, as we’ll need 28 of your body measurements. Choose the one that best suits your needs!

Bodice basic block. What is a basic block, dress basic block, torso basic block, skirt basic block, trouser basic block. Basic blocks for pattern making.lock, dress basic block, torso basic block, skirt basic block, trouser basic block.

Standardized Basic Block

Start pattern making immediately

Visit our partner site, DesignLab.London, for a variety of bodice basic blocks available in multiple sizes. These serve as an ideal starting point or base pattern for your pattern-making project. Explore the collection, select your preferred style and size, and download it to proceed with your project.

Master Digital Pattern Making in Adobe Illustrator with our Free course Adapt basic blocks into finished patterns

Bespoke Basic Blocks

Craft a personalized basic block designed for your unique measurements

Looking for a tailor-made basic block for this project? You’re in the right place. Construct your personalised basic block in the Lab by providing your measurements. Simply create a profile, input your measurements, and utilise this profile to design a range of basic block styles. You’ll need the bodice basic block for this project.

Continue Your Pattern Making Journey!

This lesson marks a key part of a whole series designed to transition you from manual to digital pattern cutting in Adobe Illustrator, making your pattern making process more faster and far more precise. Are you ready for the next lesson?


  1. Ann Clemens

    I’m learning a lot from this course and will be signing up when I find someone that can take my measurements. I have been trying to download the cutting table but have not been successful. Is this still available.

  2. Charlotte

    How do I effectively add sizes while keeping the same proportions/angles If that makes sense? I would like to be able to scale my pattern to larger sizes but I’m unsure of how to do that without having to make the pattern all over again. I might have completely missed something!

    • Ralph Pink

      Hi Charlotte, thanks for your comment.
      Unfortunately, that’s grading and something that we do not have tutorials on. You will need to either redraft your pattern for each size or pay a grader to grade your pattern to fit larger and smaller sizes.

  3. Frank

    Hello, I just found you on YouTube and you are great! I took your pattern making course and it was a great help for a beginner like me. .. So…. I do leather work and sew by hand and because of your great course I am starting to create my patterns in AI. No problem with the shapes but when I go to add a stitching line, I created using the pattern brush, and apply it to say a box and then the same stitching pattern to a different sized box that would be sewn together, the stitching spacing doesn’t match up. So I guess what I am trying to say is I need my 2mm high 45 degree diagonal lines that are 3.38mm apart from each other (that’s the distance between the pricks on the pricking iron) to stay the same distance apart no matter what the size or shape. Make sense?

    Thank you for your time!

  4. Alison

    When I try to use the scissor tool I keep getting the following note on screen. What am I doing wrong????

    “Please use the scissors tool on a segment or an anchor point (but not an endpoint) of a path.”

    • Ralph Pink

      Hi Alison. The scissor tool cuts a line (path/segment) or a joined corner (anchor point) creating two objects from one original object. The error you are seeing is appearing because you have already cut the path/segment at that point. I hope that helps?

  5. Mary


    I have been really enjoying these videos. One issue I am having is I do not see the seam allowance brushes. I do have brushes enabled and I have been using the file “Cutting table CC compatible” but it only shows the basic brush. Is there a way I can download the brushes separately?

    • Ralph Pink

      Hi Mary.

      You can find the brushes on the cutting table download. Take a look at the bottom of the post page. You’ll see a button. Click it to download the Cutting Table. That being said, I would recommend using the other technique for adding seam allowance, it’s quicker far more reliable!


  6. Barbara

    The great courses!! I love them. I learned much moore as I supposed.
    Could I have some question – can we use adding seam allowance brushes as a grading form?

    simple grading method in AI this is the only one tips I miss

    • Ralph Pink

      Hi Barbara.

      As far as I am aware you can’t grade a pattern using the seam allowance brushes. A pattern does not grade up or down by simply adding 0.5cm or 1cm to the entire outline of the pattern. You need to know how and where to manually grade a pattern. The pattern is expanded or reduced in various areas by different amounts. The amount and area of the block that is expanded is something you need to learn or study. You can probably tell by my answer that I’m not a grader and don’t have that knowledge. But thank you for your comment!

      • Barbara

        thank you for your answer Ralph
        I think you’re right!

        hmm.. I have some idea how to grade in illustrator.. but firts need to test this method on the several patterns how it works 🙂

        • Justine L Kohn

          Grading in illustrator is actually a lot easier than you might think. There are two basic ways. The first is to section off your pattern into a grid, placing lines where the body grows or decreases. Then using the Pathfinder: Divide separate the sections. This would be similar to how you would slash and spread a pattern to grade it without a grade ruler. Then you would move the sections up and over using designated sides as your zero point the amount for your grade rules. Then using the pen tool, draw in the new lines using the spread sections as a guide. The second is to use your direct selection tool to move different anchor points or groups of anchor points up and over the specified amount, This method more closely mimics how you would grade using a grade ruler. The best part is there is a tool that makes grading the in between sizes really fast, so long as the sizes use the same grade rules. For example, most sizes from 6 to 12 have the same grade rules. You start with size 6 then grade straight to 12 not worrying about sizes 8 and 10. Then once finished with 12, select both blocks and use the blend tool with specified steps and it will evenly grade sizes 8 and 10. Expand the blend group. Then if you like them nested a certain way you use the align tools

  7. Lynne

    Hiya…can you tell me if the e-pattern has seam allowance already accounted for. I put in seam allowance but its not showing up when I import to illustrator. If yes, then do I need to use the brushes on cutting mat and delete the outer line or does the e-pattern need seam allowance adding

    • Ralph Pink

      Hi Lynne.

      Our ePatterns don’t come with seam allowance. They are editable files that are designed to have the seam allowance added in after the design elements have been added to the pattern. You will need to add your own seam allowance to these patterns.
      You can do this by using the cutting table brushes. Delete the inner line and keep the outer line. The outer line is your cutting line.

  8. Emma Doll


    Thanks for all your helpful videos! There’s a third function similar to the one Britta has mentioned, it is called offset path. Object/offset path/ input distance. Use the direct selection tool to delete inner line and manipulate. It might even be the same tool..not sure- just another way to get there. ( I am using CC 2017)

    Thanks again!

    • Anonymous

      I’m using this method and it’s so straightforward.

      • Ralph Pink

        That’s great news! I’m glad it is helping you. Enjoy!

  9. Dave Hickman t/a 205 GTi covesr & trim

    I am an upholsterer, specialising in replacement car seat covers. I am in the middle of digitising a number of my patterns via the tracing jpg route, in Illustrator. I tried the modified brush method, but found it too fiddly and rather laborious to be honest. I the investigated the aforementioned by Britta.
    This certainly seems easier and does exactly what is required without all the extra end point editing of the brush method. Not intended as a criticism but merely a confirmation of the validity of the method
    Dave H

    • Ralph Pink

      I totally agree. I’ve recently tried the technique and it is a very clean and refined way of applying seam allowance to a pattern. I’ll create a tutorial and post it here to demonstrate the process for other users. A big thank you to Britta for suggesting it!

  10. Britta

    What a fantastic job you’ve done with these tutorials! Really simple and to the point, so bravo to that!

    I do have a couple of questions to this particular tutorial though. When working with and generating seam allowances there is another option and that is to use Effect/Path/Generate Outer contours – and then select whatever distance you’d like your seam allowances to be – and then Direct selection tool to manipulate specific anchor points as needed. Any thoughts on that option vs. using brushes?

    The second question is why you’re adding three strokes to each brush, if you’re only going to use two of them (in the tutorial you demonstrate how to remove the innermost stroke). It just seams like one step too many, if you understand. 🙂 I’m sure there is a good explanation.

    • Ralph Pink

      Hi Britta. Thanks for your comment. I haven’t hear of that technique before, so if it’s quicker i’d happily use it. I’ll give it go and possibly post an add-on tutorial to demonstrate the concept to our users. Thanks for your help! Collaboration and info sharing is what we live for.

      • Britta

        Thanks for your reply – do check it out and see if you like it. If nothing, then you’ve at least tried it. 🙂

        With regards to my Q on brushes, I realized why 3 paths is needed (as the brush is applied to the centermost path), so never mind that question.

        Also, again, it’s ah-maze-ing that you’ve done all these tutorials and are providing them for free. They’re really high quality so kudos on that! 🙂

      • Ralph Pink

        I’ve actually now started using this technique and it’s so incredibly simple and effortless! Thank you for the suggestion it worked a charm.

    • Vivienne

      Hi Britta
      I tried with a few alterations as I lost the original line to start with and only ended up with the offset.
      I ensured the original lines were grouped and made it a dashed line.
      Then Cmd C copied it, then Cmd F to put it directly on top of the copied line.
      Next I used Effect/Path/Offset path to create the outer line (from the copied line),
      Finally I changed the offset line back from dashed to continuous

      I still only in training mode with Pattern Lab and loving it, I really would like to know if this is usable as it seems so much simpler.


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