Grafis CAD - Construction Parameter X Value Magic!

With the rise and fall of the hem line so is a pattern makers job never done. The adjustment to these variable lengths as the seasons change and as fashion dictates is what makes the construction parameter X value such an outstanding feature in Grafis CAD Software developed by Dr. K. Friedrich. A skilled and forward thinking patternmaker and production team can plan and use this table of X values to change and adjust styles by only changing the x values. This application requires a little abstract thinking, a level of thinking that removes us from the here and now, allowing a hypothesis of how the style might develop and change in the future.

Let me explain further, X values are numerical values and can be represented as length, distance, radius and angles. Before pattern making begins you need to decide where to use these values, as they cannot be put in after the style has been completed and must be defined before it can be used in a construction step. But the values can be altered and changed after completing the style, but the changes are only visible after clicking ‘test run’ and ‘grading’. Therefore, as with the example of the bodice with CF overlap  firstly with 20mm and then with 70mm as seen below; the style is changed by simply changing the x value relating to the overlap width and button position from bust point height.

Where’s The Window?

X values input area window is found under the Extras menu or shorthand keyboard command ‘Ctrl X’. 

There are 3 different types of x values, and the application is the same for all types.

1. X values of non-interactive basic blocks – Grafis defined.
2. X value of the construction record – user defined for individual pattern pieces.
3. X value of all parts – user defined and refers to all parts as Global x values - for example seam allowance and hem.

2 and 3 are where you would plan ahead and consider the garment and construction steps to input and use x values, for flexible pattern modification later on, in alterations and in style variations. For example if you have a change in fabric for a garment heavy fabrics require a wider hem, whereas light fabrics usually have a small narrow hem.

The following tools offer x value options and should be considered first when planning your construction and how they can be used in the future for flexible pattern modification.

Parallel menu: distance in mm.

Raster menu: number of points and point distance.

Lengthen/shorten menu: final length and length difference in the sub-menu in Points and Line construction.

Relocate dart: % of dart.

Spread menu: distance in mm.

Curves menu: bind start point, final point and base points of the curve new.

Transformation menu: move amount, scale factor and rotation angle.

Points and lines menu: in millimeters the length of a line and relative values for point construction.

Circles and Rectangles: Radius of the circle, height and width of rectangle.

The X value window displays the following information and input areas. The List selection is for either Global or Active Parts.

Global X values are the x values of all parts in the style, for example seam allowance self and lining, the ease allowance, and distance for markings and adaptation factors for stretch.  Global X values are identified with a G for example ‘XG3’ stands for the 3^rd X value for all parts in the X value table, whereas X3 stands for the 3^rd X value for the active part in the X value table. Active parts are pattern pieces that have X values unique to them. Upper and lower case letters makes no difference, it’s not case sensitive.

There are 3 display options, Edit view is the most detailed view, Short view shows only X values and standard values and Interpolation view (meaning: Insert view) specific sizes can be viewed by clicking size in size name field.  (I looked up Interpolation and here is what the free dictionary had to say, 1. To insert or introduce between other elements or parts. 2a. To insert (material) into a text. 2b. To insert into a conversation).

To become familiar with the X value table this simple exercise from the free download manual is a good place to start. The only way to increase your knowledge of Grafis is to complete these exercises.

To add new X values to a basic block complete the following steps. Call Bodice 10 and construct a parallel on the CF for a 20mm over lap and the position for the first button.  To do this, open X Values from the Extras menu, select List: Active part and switch to Edit view. Have a play by adding and deleting X values using the buttons, ‘Add New X Values’ and ‘Delete Last X Value’, you will see the active part list is easily populated with x1, x2, x3  followed by _xxxxx_x= etc.  

When you are comfortable, name x1 ‘overlap width’ by double clicking on the comment line, or by clicking Edit Entry button.  And give the 20mm value to x1. Proceed to x2 comment line and enter the text ‘button position at CF from Bust pt’ and assign a value for x2 as 20mm. Close the window. Work on the bodice, by selecting the Parallel menu enter the distance value as X1 and click on the CF, the overlap appears at 20mm. To insert the first button position, select the Points menu using ‘point with distance to a base point on a line’ with the absolute distance value as X2. First click the bust point, then click the CF pointing in the hem direction. Grade the construction, from Extras menu, select Size table enter sizes N40, N36, N44. Stack at bust point.

Overlap and Button Position

Size Matters, Especially When It Comes to Garment Proportion!

Size related X values, this is interesting for grading. Adding, editing and deleting ‘size’ related X values is only possible in Edit view. In the X values window (Ctrl X) the Size name is listed to the right by clicking on the X value entry, the size chart becomes active and simply by selecting the size name it is inserted into the table for editing. As with the example of the back yoke on Bodice 10 where size 42 X3 ‘start of yoke on CB from neck’ has 10mm added from size to size, therefore size N40 will be 120mm on CB from neck and N42 =130mm on CB from neck.

Bodice Back with Yoke Position

note to self: X values of the basic block are not subject to editing, adding or deleting.

There is so much more to X values than first meets the eye, just for starters let’s take a look at the rules for size related value assignment. 

We know that X values can be altered in relation to size as seen above, but it’s not necessary to assign each size with a value, especially if the x value is identical for all sizes.

The next exercise is to create a shirt with a flared hem, working only on the bodice front of bodice block 10, call the bodice and delete lines and points that are not required. Portions of the bust dart are to be relocated into the side seam and hem, the portion allocation is size dependent.

Size _N36 and up to Size _N40 = 100% the complete bust dart relocated into the hem

Size _N42 = 25% of bust dart into side seam and remaining 75% into hem line.

Size _N46 = 50% into SS and 50% into hem.

Add X values to table under Extras menu, X1  ‘portion bust dart in side seam’ = 25. X2 ‘portion bust dart in hem’ = 25.Note: All darts remain open without dart hoods. Relocated dart using the function on relocated dart, x1 into side seam and x2 into hem. Construct dart hoods on bust dart and side seam dart, link hem as a curve. Link side seam, armhole and shoulder including dart hoods. This is to allow you to apply a Global X Value for seam allowance and hem in the next step.

Add Global x values to the table under the Extras menu, select global values and Add New X Values. X1 ‘general seam allowance’ 10. X2 ‘hem allowance’ 20. Using Parallel menu enter XG1 for seams and XG2 for the hem. Close with Corners.

Shirt with Flared Hem

Only now, can the size related portions of dart allocation be implemented (remember this is a percent). 

Size Dependent Dart Allocation

To make it easier to view the result I selected under the Extras menu ‘Size Table’ and to the left of the list of sizes you can tick the sizes you want to see and by un-checking the others those sizes become invisible. Then you can see that on the _N38 the bust dart is in fact 0 and 100% into the hem. And on the size _N48 nothing into the side seam, 50% into the hem and which leaves the bust dart remaining 50% open at the shoulder.

Size List View _N38 & _N48