“Balance can be created by the uneven placement of detail” Mark Garbarczyk.

CAD - “Computer Aided Design” or “Corsets Are Digitised”.

As an intimate apparel designer / pattern cutter, it is very rare these days for me  to put HB to parchment. In fact, I would say that 97% of my design work, including the “pretty pictures”, is undertaken on a computer; 100% for the very important technical “flats” drawings.

For me it’s a case of repeatable ACCURACY. If you have been following the bra pattern drafting / making articles you know that I work to the millimetre, and sub divisions thereof, and a pencil line can be one millimetre or more wide. Please continue to use pencil and paper if you are happy with “hands on”, but do have a go at using CAD. When first using CAD software you may find that the size of the blocks / patterns parts on the screen seem confusing, but this will soon pass.

Firstly, let's get something right, A COMPUTER WILL NOT DO IT ALL FOR YOU! A computer is just a tool, so you still have to do the work.

In this article I will be referring to the CAD package Corel Draw, only because I have been using Corel Draw since version 3, through versions 5, 7 and 11. I now use version X3 (13), but most of the terminology / way of working in the article is compatible with other CAD packages (other top-notch retail CAD products include Adobe Illustrator, AutoCAD and AutoSketch).

Below are some additional commercial /industrial pattern drafting CAD software systems (which are a-terrifying-lot of money and sometimes unfriendly):

• Modaris, made by Lectra
• Accumark, made by Gerber
• Master Pattern Design, made by Pad

Usually retail CAD packages have very good built-in help files and online community forums for tips and tricks, unlike some commercial /industrial pattern drafting CAD systems that come with NO built-in help so you have to “pay through the nose” for their training courses! I know at least one company that will not sell you their CAD software until you have been on and paid for their training course!

I hate to talk in terms of a “learning curve”, so I just tell people to become a child and play with the CAD software to see what it will do. After all, that’s how children become “whizkids” on computers, spending hours on end in their bedrooms playing with them.

Next we need to define the difference between a CAD program and a Graphics program. A CAD program can also be called a “Vector drawing” program and a Graphics program can be called a “Bit Map editing” program. In other words, when you zoom right in on a line or object in a “Vector drawing” CAD program the line remains a solid line, but in a Graphics “Bit Map” program when you zoom in on a line it appears as a string of small squares or bits (and is therefore  fuzzy).

 

So a graphics (bit map) program such as Adobe Photoshop will not do for accurate pattern drafting.

Now: time to check the bank balance.

The shopping list.

• A desktop computer or laptop (draft a bra on the train or plane!),
• CAD software,
• Large monitor: don’t go too big or the screen can be overwhelming and tiring on the eyes. (Remember to take regular breaks from the computer and have a nice cup of tea!)
• A printer, preferably A3 paper size or bigger (yes I know they’re more expensive than A4 size printers),
• A scanner, to input / scan in your old patterns and COPYRIGHT FREE book patterns.
• A graphics tablet and pen (right): this is an excellent alterative to using a mouse to draw with (and more natural). It's a bit tricky to start with, but how long did it take you to learn to use a mouse with the computer?

 

 

 

In CAD you can have many “sheets of paper” and copy / paste drawings to new pages so you can “back step” through your pattern drafting steps if you find a mistake. You can also build up a set of master block pattern files and copy the master parts into a new file, then modify them to create a new garment pattern without ever using a single sheet of real drafting paper. Remember the “your size” master darted bra cup block in the bra articles - how many times in the articles have I asked you to copy the bra cup block?

There are drawing tools down the left side of the screen. Size and position boxes are above the drawing area so you can type measurements in, and the usual drop down menus across the top of the desktop.

In this article on CAD I will only be giving you a taste of pattern drafting and drawing using a computer; unfortunately I do not have the time to write a 200+ page “how to” book on CAD and you may want to use a different program from mine. So I will cover a very basic run through of a task that some of you may have already done with pencil and paper: copying a corset pattern from one of those “historical corset pattern books”.

In your CAD program, set up several pages that are at least A1 paper size in landscape.

Look at the “pattern” page in the corset book and find the scale. Is it in inches, centimetres or a grid?

You now need to draw spaced lines or a grid that match the book scale / grid on your CAD page. Use the line pencil tool to draw the lines.

In Corel Draw you can hold down the “Ctrl” key to draw straight horizontal or vertical lines and type in measurements to space the lines as per the scale. You can also use the “place duplicate” command (see the programs help file)

Now scan into the CAD program the pattern you are working with. In CD (Corel Draw) this is called “acquiring an image”.

Around the page scan picture you will see eight small black squares. These squares are grab handles that allow you to enlarge, shrink or stretch the picture (if you do not see the grab handles, click on the picture). Use a corner grab handle to enlarge the picture until the printed scale or grid match / line up with your grid lines. If you use the grab handles along the sides or top / bottom you will stretch the picture / corset out of proportion, so just use the corner grab handle squares.

The picture enlargement takes a little time to get right and you may need to zoom in on the inch or centimeter scale/grid (if there is one). In CD (Corel Draw), lines and other objects are placed in “layers”; if you cannot see your grid lines over the top of the picture you need to rearrange the “order” of the layers / objects, from the menu “Arrange” – “Order”

Now copy and paste everything on the CAD page to a new page. Remember save, save, save as you go.

You need to trace around the corset parts using the pencil tool, the best way I have found is to draw short, connected straight lines along the corset picture lines. Later I will join, smooth off and curve the lines using the lines' “nodes”.  CD does have a built in “trace” program but I have always found that it produces more “artistic” traces than usable pattern drafting line traces.

When you have traced around all the corset pieces, copy and paste everything on the CAD page to a new page and delete the picture on the new page leaving the trace lines. Save, save, save as you go.

The mystery of the “node”.

All lines and shapes in CD have nodes attached to them (control points in Adobe Illustrator). The nodes allow you to control and shape a line or object. You can delete nodes, add nodes, break nodes apart (cut up a line or shape) and join nodes (connect two lines together). You can turn a straight line into a curved line by simply changing the type of nodes attached to the line. You need to read your CAD help file and play with nodes (control points) to get a full understanding of how to use them. Nodes are important but I do not have enough room in this article to go through everything you can do with them.

So now we have a set of traced lines with a lot of nodes, so we need to remove some, join some and turn some into curved line nodes.

Select the Node tool and click (touch) on one of the lines and you will see very small blue squares on the lines. These are lines nodes. Click on a node and you will see its control / shaping arrows.

Again, I’m sorry but it would take up the full website to go through the step by step of tidying up the trace lines to give you the basic outline of each corset panel, but you should end up the basic outline of each corset panel with as few nodes as possible on the lines, and the line ends joined to form the outline corset panel shapes. Take your time, because sometimes if you delete a node on a curved line, the curvature of the line can change.

When you have the outline of each corset panel, you can start to correct and change the shape / size of the panels. This is where CAD really comes into its own for pattern drafting. We will start by checking the curves of the top and bottom hemlines of the corset panels and tidy up the “flow” of the curves.

For this you can use the “Snap to” function and the “Rotate object” function. The "snap to" function allows you to place an object accurately up against another object: you move an object close to the other object and they “snap” together at a point that you select.

Now if we click on one of the corset panels twice we get a set of “rotation and skew” grab handles plus a “centre of rotation” circle/point. We can move this centre of rotation circle/point to the point where the two panels touch.

Then we can rotate the panel so that the seam lines of both panels touch at the top; the snap to function will help again.

We can do the same for all of the panels so that we can see the flow of the top hem line.

To correct any “hiccups” in the curves, simply use the Node tool. Click on the panel hem line then click on a node and move the node control arrow to correct the line curve.

We can follow the same procedure for the bottom hem of the corset panels.

When you have corrected the hemlines, straighten up the panels again by clicking on each panel in turn, and type 0 degrees the “Angle of rotation” box above the drawing area.

We are ready for the next task, to adjust the size of the corset for around the body size and body length. To measure the size of the panels you can “pull out” guide lines from the rulers at the top and side of the drawing area and snap them to points on the corset panels.

When you have worked out how much to alter the size of each panel, copy the panels to a new page (in case things go “bottom up” so you can “back step”). Draw a line down the centre of each panel.

For each panel, zoom in on the point where the new centre line touches the top hemline. Using the node tool, click on the hemline and add a node at the intersection point of the centre line / hemline. Then break apart the new node; this will cut the hemline in two. Do the same at the panel's bottom hemline, then go to the drop down menu to “Arrange” and select “Break Curve Apart”. This will split the corset panel into two halves.

You can now move one of the panel halves out or in by the right amount. When moving an object you can hold down the Ctrl key to “constrain” the movement to a horizontal or vertical movement. Use the rulers and pull out guidelines to get the size change right. You can also type the measurement change into one of the object “position” boxes above the drawing area.

When you have changed the size of the panel use the “Select” pointer tool and the “Shift” key to select the two panel halves. Go to the drop down menu “Arrange” and select “Combine”; the two halves of the corset panel will join back together.

Use the Node tool and select the nodes on the ends of the top hemline lines and click on “Join” to connect the nodes and join the lines. Do the same with the bottom hemline halves. You now have a fully resized panel. Repeat for each panel.

You can do the same to change the length of the corset panels; just node split the panels horizontally (usually at the waist line level).

When you have done all the resizing, check the flow of the top and bottom hemlines again, snap to and rotate, adjust node arrows.

Now to add seam allowance to the panels. This is very, very easy in Corel Draw X3.

Click on a corset panel, select the drop down menu “Effect” and select “Contour”. A “docker window” will appear at the side of the page.

In the window, select “Outside”, type the amount of seam allowance in the “Offset” box, set the “Steps” box to “One” then click on “Apply”. And in the blink of an eye you have added a seam allowance around the corset panel. How cool is that!

If the seam allowance dos not go fully around the panel then you have two or more nodes that are not joined together (a broken line) on the panel outline.

To add different seam allowances to the panel, say 5mm for the panel-to-panel seams and 10mm for the eyelet platform area, click on the panel again and do the Contour effect again but with the different allowance in the Offset box.

Before you print out the corset pattern parts, give your pattern a professional look and add text to the parts. Pattern name, part name /number, size, number to cut, seam allowance, fabric, date, weave/grain line and any other pattern marks and information that is needed.

Use the “Text” tool. You can also rotate the text to fit along a particular part of the pattern.

Now, how do we print out a sewing pattern that may be far bigger than a single A4/A3 sheet of printer paper, i.e. the pattern for a full Victorian ball gown, perhaps?

The secret is “TILING”, sometimes known as “Poster” printing. We basically tell the program to print out the pattern at full size over several sheets of paper, and then we stick the sheets of paper together, i.e. we do some tiling. That’s why I suggested that you use an A3 paper size printer - fewer sheets of paper to stick together than A4!

You could also save the pattern to disc and use the services of a “Print Shop” who will have a very large format printer / pen plotter.

To tile print in Corel Draw, set up the printer from “File” – “Print setup”. Next, select the pattern parts that you would like to print (you may need to move the parts around and together to save sheets of paper), select “File” – “ Print preview”. The print window/page will open up. Select “Settings” – “General” and click on “selection”.

Now select “Layout” and click on the “Print tiled pages” tick box then the “Tiling marks” tick box, in the “Tile overlap” number box type 15mm, this will give you 1.5cm of paper overlap for the glue. The “Tiling marks” will give you printed alignment marks on the sheets of paper to help to trim and stick the “tiles” together.

Click on “Apply” and “OK”. You will see a representation of the pattern parts arranged over several sheets of printer paper.

Lastly select “File” – “Print this sheet now” and your printer should now start to churn the “pattern tiles” out.

By the way, you can use the same process to print out a big “Happy Birthday” banner or a poster for your next corset sale.

The best glue to use to stick the paper together I have found is that white “in a lipstick” type glue. When the glue is dry (only a few minutes) cut out the pattern parts and you are ready to cut and sew! Did you remember to save your file?

Of course, if you are really rich, you could forget the paper pattern stage altogether and get yourself a nice CNC (computer numeric controlled) cutting table, just like the big boys and girls play with, and go straight to fabric....

No, I do not have one! But I have used a CNC Laser cutter. The heat of the laser seals the cut edges of synthetic fabrics so they do not fray, very very cool.

Important!

There is one small drawback with using Corel Draw for pattern drafting that I have always found a strange omission from the programme. Corel Draw will not give you the true length of a curved line. It will only tell you the “straight line” length of the curved line from one end to the other. So measuring the length of a curved seam line is virtually impossible (but not completely impossible, play with “Fit text to curve”).

But help is at hand in the form of add-ons that you can download and use in the programme. One very good and FREE add-on is “JH_curvelength” by MacroMonster.com.

It comes in the form of a “VBA macro”. Download and unzip the “gms” file, then copy the file to Corel Draw’s GMS folder on your PC’s hard drive at: -

C:\Program Files\Corel\CorelDRAW Graphics Suite 13\Draw\GMS.

Then to measure a curved line, select the line with the pointer tool, select the drop down menu “Tools” – Visual Basic – Play. A window will open up and select in the “macros in” box “JH_curvelength” cm or inches then click on run.

The length of the line will be displayed in a new box to THREE DECIMAL PLACES! Accuracy, I love it!

NOTE that the line must be disconnected from any other line to be measured correctly.

So that takes care of historical corset patterns and old paper pattern work but to get the most out of a computer pattern drafting system, you must try “starting from scratch”. Again, you can get into CAD drafting by following the pattern drafting instructions from books or my bra making articles and use the computer instead of pencil and paper. Do not be fearful of the computer, play and experiment with it, just as a child would.

Talking about using pencil and paper, not all of us are highly gifted artists. I said at the start of this article that I now do 97% of my design work on computer, including the “pretty pictures” drawing. I do still draw and paint but I also like to “draw” on the computer. If you are not gifted in the art department but would like to do some garment design illustrations (pretty pictures), the computer can be a help with this.

If you get the hang of tracing a corset pattern on the computer then it’s a simple jump to tracing a human figure from a magazine picture scanned into the computer. The best picture to use is someone wearing a swimsuit so you can see / trace the body shape. Full length and three quarter length body pics work well. You can also “stretch” the body trace on the computer to get a classic “nine heads high” form.

 

Do not try to trace the features of the face but just use the outline of the face, head and hair. You are just after a basic “fashion figure” outline to “dress” in your design ideas.

When you have traced several body outlines you can start to use the artistic drawing tools and shape colour / pattern “fills” of your CAD program to create your latest spring / summer collection.

Four garments coloured and filled with patterns from real fabrics scanned into the computer, in Adobe Photoshop from outlines drawn in Corel Draw.

So there you go, don’t just use your computer to send e-mails to friends or to have a quick game of “solitaire”, DO SOME DESIGNING!!

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