Our Most Frequently Asked Questions

Find quick answers to commonly asked questions about our products/services. If you can’t find what you need, our customer support team is here to help. Thank you for choosing us!

Computer screen with a digital pattern making program, Adobe Illustrator open, showing a dress basic block pattern, on a desk with modern design tools.

Need Assistance with Our Pattern Drafting Tools or Resources?

Fantastic, we’re here to assist! Whether you have questions about our pattern drafting software, standardized basic blocks, tutorials, or pattern cutting techniques, we’re ready to support you. Feel free to shoot us an email or leave a comment, and we’ll make it our priority to get you the information you need. And if you bring up something new that we haven’t tackled before, we’ll add it to this page to aid our online community.

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Why doesn't my drafted block fit accurately?

There are a number of reasons for why your block might not fit. The most common reason is that you have taken incorrect measurements. We have produced a troubleshooting guide to help you resolve the most common issues with your block. The most important part of this guide is how to:


#2a Troubleshooting the Basic Bodice and Torso blocks

#2b Troubleshooting the Basic Skirt block

What is a basic block?

A basic block (sloper in American terminology) is a basic bodice, sleeve, skirt, pant, or dress pattern that is made to fit a particular individual, size, or mannequin exactly or accurately. It has minimal darts or design features and is usually sewn with muslin or some other inexpensive light-weight cotton fabric. A basic block is used as a template to create more complicated designs or styles, once the fit has been perfected for that particular customer or client.

I've made a basic block. What do I do now?

Once you have created a basic block, you should either download it as a PDF for paper pattern cutting or download it as an ePattern for digital pattern cutting.

We provide a range of tutorials that teach you how to pattern cut your blocks into a range of different designs, adding necklines, sleeves, body panels and much more. You can find all of our available tutorials in the Courses tab on the menu.

All of our tutorials are geared towards digital pattern cutting in Adobe Illustrator, however, you can still follow these tutorials to produce patterns using the paper pattern process, since the techniques used are the same for both digital and paper pattern cutting.

What is a PDF pattern?

PDF patterns are downloadable patterns which you can print at home on a normal home printer in a variety of paper sizes: A4, A3, A2, A1, A0, and US Letter. You then assemble the individual pages together with sellotape (we recommend scotch tape) to create a full size, physical pattern ready for construction and alteration. These patterns are generally used by customers who prefer to use our basic blocks for manual pattern cutting, rather than digital pattern cutting.

How do I print and construct a PDF pattern?

Please click here to take a look at our helpful guide. It will ensure you’re using the right settings everytime you print your multipage PDF patterns.

My PDF pattern printout is missing some lines.

If you are using the Chrome browser and displaying or printing a PatternLab PDF file with the internal PDF viewer you may notice sometimes that seam lines will not be correctly drawn.  They may be partially or completely missing.  This is a known problem with the Chrome browser versions before V53.


As a workaround, save the PDF to disk and open the PDF using the Adobe Acrobat Reader DC for viewing and printing.  Download Acrobat Reader for free here.

What is an ePattern?

An ePattern is an editable version of your basic block, saved in the form of an SVG file (Scalable Vector Graphics). ePatterns give you the ability to edit or re-draw the lines of your drafted blocks and work in conjunction with our online courses and tutorials. Our courses will teach you how to add new design features such as necklines, sleeve variations, collars, button stands and much much more.

An ePattern can be imported or opened in a variety of different editing suites that accept the .SVG format, however, we highly recommend using Adobe Illustrator to edit and customise your ePatterns, as it by far the most comprehensive package available, plus all our tutorials are created within Adobe Illustrator.

What is a toile?

A toile is an early version of a finished basic block or garment made up in a cheap material so that the design and fit can be tested and perfected before making the finished item. Calico is usually the preferred choice when making a toile, however, the toiling material choice often depends on the what the actual finished garment will be made from. Using a similar material when toiling often helps when it comes to understanding the weight and drape of the finished garment fabric, therefore making the toile a more reliable example of the finished garment.

What is a dart or dart manipulation?

Darts are folds (tucks coming to a point) and sewn into fabric to take in ease and provide shape to a garment, especially for a woman’s bust. They are used frequently in all sorts of clothing to tailor the garment to the wearer’s shape or to make an innovative shape in the garment. The fabric may be thought of as flat, and a dart has the effect of removing a wedge-shaped piece and pulling the edges of that wedge together to create a shallow cone. This effect can be seen quite easily with a paper pattern by pulling together the edges of a dart intake as it would be sewn. Since the fabric is generally more flexible than the paper the fabric will shift around the apex of the cone and form a softer, but still curved, shape. In a garment, a dart ends in a point at a full area of the body.

A dart in a flat pattern has two important properties: its point, the point in the pattern at which the dart aims or converges, and the intake, or the amount of fabric taken in or removed. Since the dart can extend toward any edge of the pattern without affecting fit, the length of the dart intake at the edge of the fabric is not a good measure of dart intake. Rather, the angle subtracted from the pattern by the dart is what determines the dart’s intake.

Manipulating darts in flat patterns

As long as the focal point of a dart and its intake remain the same, a dart can be rotated around its focal point, or stylized in one of several ways without affecting the fit of the garment.

Slash-and-spread dart rotation

An easy way to rotate a dart on a flat pattern is to slice a straight line from the dart point to another edge of the pattern (the slash). The two pieces thus created can then be pivoted (spread) at the dart point to shift the dart to the position of the slash.

Pin and pivot dart rotation

The pin and pivot dart rotation technique requires tracing a new pattern from the original. First, the pattern with the dart to be rotated is set on top of another piece of paper on which the new pattern will be traced. A pin is pressed into the dart point to hold that point in place. Then one leg of the original dart and an arbitrary part of the original pattern is traced onto the paper. This tracing starts from the one dart leg and continues from there to the new point where the dart will reach the outside of the pattern piece. The pattern is then rotated around the pinned dart point until the other dart leg lines up with the traced dart leg. Tracing can then continue from the same spot on the original pattern. The pattern is then removed and the new dart legs drawn between the dart point (marked by the pinhole) and the gap in the pattern created during rotation.

Dart Equivalents

Pleats or gathers in the fabric can be used as for the same purpose as a normal stitched dart. These are called dart equivalents. Darts can also be worked into style lines.

Named Dart Styles

There are two kinds of darts that are common in blouses for women:

Vertical Darts – These are sewn from the bottom of the blouse to a point generally around the bustline. This type of dart may be found in the front, rarely in the back of a garment and are used by the garment maker to pull in the bottom of the blouse towards the wearer’s waist.

Bust Darts – These are short triangle folds that provide space for the breasts such that the fabric under the breasts isn’t hanging, rather is fitting closer to the wearer. There are several subtypes of bust line dart: Center, Waistline, French, Side seam, Armhole, etc.

What is seam allowance?

Seam allowance is all about personal preference and very much depends on the Sewist and the machinery they are using. Seam allowance is the space or area between the edge of the fabric and the line of stitching, on two (or more) pieces of material being stitched together.


It is the extra material needed to prevent the seam from fraying and eventually coming apart. If a garment is sewn together without seam allowance, it will no longer be the correct size as the line of stitching will encroach into the fit of the garment, therefore making the garment not the intended size.


Drafting your pattern with no seam allowance is common when the drafted pattern will be further altered. Generally,seam allowance is only added once a pattern is finished and ready for toiling or mock up in material. We always recommend making a toile or mock up of your drafted pattern first, to check the fit before adding further design elements.


Standard seam allowances tend to be 1cm or 5/8”. Your sewing machine cover plate will most likely have a line at this distance from the needle. Measure the distance between the needle and the markings on your cover plate and input this as your desired seam allowance. When constructing your garment, line up the edge of the fabric with the markings on your cover plate to ensure you are stitching the correct distance from the fabric edge. Use this standard seam allowance for all your patterns, allowing you to know how far in from the edge of the fabric to stitch, thus constructing your garment to the correct size.

What is ease and how does it affect your block?

What is Ease?

Ease plays an important role when building a pattern, it determines how your garment fits. Ease is the difference between your actual body measurements and your finished garment measurements at the bust, waist, and hips.

The amount of ease added to a pattern changes the fit of your block. There are generally two types of ease that can be used when drafting your basic blocks: wearing ease and design ease.

Wearing Ease

Wearing ease is the most commonly used fit and gives the minimum amount of extra room needed to allow for comfortable, non-restricted movement, allowing you to sit, move, raise your arms and breath easily. Any more ease than this is considered design ease.

“Automatic Fit” analyses your unique measurements and adds the correct amount of wearing ease to create a comfortable fitting block.

Design Ease

For example, let’s look at design ease on the waist. Place the tape measure around your waist and expand it until you are happy with the distance from the body in terms of your design. To calculate how much design ease you need, subtract your actual waist measurement from this design measurement. The amount left over is the design ease. This concept also applies to both bust and hips.

Negative Ease

Negative ease is often used when a basic block needs a far closer fit for…

What is an automatic or custom fit?

Automatic fit

Create a well fitting and comfortable basic block can be complicated, especially when it comes to knowing how much ease you need. Unless you are a seasoned pro, you might not understand how much ease should be added to get the best fit results. To help you, we have provided an “Automatic Ease” setting for all our basic blocks. The Automatic ease setting analyses your custom measurements calculates the optimum ease (using percentages) and applies it to your block during the drafting process. We are constantly refining our ease percentages, via our testing group, to ensure the fit of our basic blocks.

Torso block example:

Bust ease: 9% of Bust measurement
Waist ease: 6% of Waist measurement
Hip ease: 5.5% of Hip measurement

Custom fit

Using automatic ease should produce a comfortably fitting block each and every time, however, there are always exceptions. We provide a Custom ease selection allowing you to override the automatic selection and manually change the amount of ease on your basic blocks.

What is the correct method when taking my measurements?

Each company or individual has their own method for taking measurements and no one style is correct, It really depends on the individual or company. This concept also applies to Patternlab – We have produced a comprehensive measurement tutorial video (on the profile page) that is designed to work hand-in-hand with the Lab software, ensuring you get the best possible result with your drafted pattern. You are free to measure the body in your own style, however, we can not guarantee the accuracy of the resulting drafted pattern.

You can watch our measurement tutorial videos by visiting the profile page and troubleshooting guide. You can also click the help icon next to each measurement when in the Profile page, to view instructions for each measurement.

How regularly should I update my measurements?

Bodies tend to fluctuate from week to week or month to month. It is important to take your measurements on the same day and toile your pattern within the week – preferably on the same day. This will provide the very best fit for your basic blocks. A garment with a closer fit or little ease will be affected by body fluctuation substantially more than say a garment with a more relaxed fit or greater ease. It is a good idea to check your measurements each month, to ensure that your profile is up to date and the patterns you are creating are accurate to your body shape.

What is a standard size chart and why don't my measurements match?

Why don’t my measurements fit the chart?

Don’t worry this is not uncommon. The standard size chart is used purely as a guide when drafting basic blocks. Women come in a variety of different shapes and sizes and not all women will fit a standard size exactly.

So what is a standard size and what does she look like?

The standard woman is a composite figure whose measurements are based on what any successful manufacturer or retailer say they are. Her figure changes at the whim of the fashion industry or whatever is perceived to be the “ideal” form, at that point in time. She is symmetrical, with an upright stance and she has aesthetically pleasing proportions. She is considered “ideal” when her measurements satisfy the majority of consumers for that particular manufacturer. Unfortunately, there will never be a universally accepted standard size because of the vast array of shapes and sizes present both regionally and internationally. Also, standard size charts are based on surveys taken from 1000’s of women’s measurements and are therefore closely guarded by the company as they have a substantial commercial value, which means understanding or defining a standard size is almost impossible.

What are they used for?

Standard size chats are predominantly used by students, professionals, and retailers to create mass-produced clothing that fits the “majority” of their customers or clients or to create high fashion garments that fit a standardised model figure.

The standard size charts that we provide, should only be used when speed is a necessity, to quickly produce a basic block, or when taking custom measurements is not an option.

Producing a custom size.

To produce accurately fitting basic blocks, we strongly recommend creating a profile following our measurement tutorial video and enter your own custom measurements into the profile page. 

Amending a standard size chart.

If your basic measurements fit our standard size chart but there are just one or two measurements that don’t fit, you can always save it as a profile and amend it to suit your needs – dramatically speeding up the process of creating custom profiles.

Why am I getting an error message when entering my measurements in the profile page?

If you enter a measurement that is far greater or smaller than the leeway provided by our system, you will see a red error message. You will not be able to use this measurement when drafting your block, as it will produce a broken or badly fitting block.

patternlab error message

If you receive an error message, it is most likely that the measurement was entered incorrectly. Please re-take the measurement, paying close attention to the measurement video tutorial provided. You can also click the help icon next to each measurement when in the Profile page. If the error persists, please check our standard size charts or troubleshooting guides to better understand our size range and whether your size is available.

Why am I getting an error or warning message when drafting my basic block?

Measurement errors

You might see an error message appear when drafting your blocks in the lab. This is quite common and could happen for one or two reasons:

Either you have failed to enter a measurement into the profile page, that is required to draft your block. To resolve this issue, simply click the ADD MEASUREMENT button to bring up your selected profile. You will see a similar red warning message appear under the measurement that is missing – Enter your measurement to resolve the issue. Your measurement must fall within the Min or Max leeway for your measurement to be accepted and the warning to disappear, both on the profile page and within the Lab.

Another possible reason is that you have entered a measurement that falls far outside the minimum or maximum leeway for that measurement. The lab can not draft blocks that are based on wildly inaccurate measurements, as it might cause the block to break. If this is the case then you will need to revise your measurements.

Do you sell blocks for menswear or childrenswear?

No, currently we only draft womenswear basic blocks, however, we will be expanding to children’s and menswear in the future so watch this space..

Should I register an account or be a guest user?

For a registered user, PatternLab maintains a permanent library of your order history and profiles. You can also specify certain preferences that the system will remember from one access to another, such as your preferred measurement unit (centimeters or inches).

For a guest user, orders are confirmed with an email which contains a link to instantly download your purchases, which you can access subsequently as many times as you wish. Any profile you create as a guest cannot be guaranteed to be available the next time you use the system. When you create a profile as a guest and then immediately register as a user, the profile will automatically be added to your new
profile library.

Do you run any face-to-face courses?

PatternLab prides itself on being 100% online. Check out our Courses page for our FREE tutorials and courses and learn from the comfort of your own home. .

I’d like to become a tester, how do I get involved?

That’s great, send us an email at testing@patternlab.london and we can start a conversation.

I want a pattern for a style or garment you don’t have.

We’re constantly working on new releases. For example, our next releases will be the stretch dress, trousers and then swimwear blocks. Make sure to keep checking for updates or subscribe so you don’t miss out.

I sent you a question on Instagram or Facebook but I haven’t heard back yet.

The best way to contact us is by sending us an email at info@patternlab.london as we check this daily. We’re old fashioned like that.

I'm interested in collaborating!

That’s great, we have a Collaborations page just for this. Get in touch via the form and we’ll get back to you.

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