The basic techniques for shortening or lengthening a pattern.

The two methods presented below allow you to make a whole set of modifications, and this on any type of pattern. You will be able to easily modify the pieces of a skirt, a pair of pants or a top. 

In both cases, the modification must be made in a coherent way in order to be able to assemble the new parts between them without difficulty. Thus, if the front is modified, the back must also be modified so that the side lines match perfectly. If the height of an armhole (on the bust) is modified, the sleeve head (on the sleeve) must also be modified.

Method A : the objective is to keep the complete structure of the pattern

The fullness and volumes of the garment are not changed.
Cut the pattern pieces in 2 and add or subtract the desired value between these 2 parts.

Key point: for ease of use, use grid paper. The lines will be used as markers to keep the parallel and perpendicular.

• Using a ruler and a criterion, draw a line perpendicular to the straight edge and the front and back middles (if the pieces have them) on the parts of the pattern to be modified. To place the line, refer in more detail to the explanations concerning the modification to be made. But in general, it is advisable to avoid placing the line on marker lines, assembly notches or clamps.

  

• Cut on the line so as to divide the pieces in 2 parts.

  

At this point, you must have defined the value to be added or subtracted.
 

To lengthen a pattern

 

• Glue a piece of paper under the top of the pattern.

• Transfer the measurement to be added to the paper, starting from the cutting line of the part.

• From this new reference point, draw a new axis parallel to the cut line.

• Glue the bottom part of the pattern to the paper, aligning the cut line with the axis drawn earlier. Check that all parts are still perpendicular to the straight line and to the front and back middles (if the pieces have them)

 

To shorten a pattern

 

• Transfer the measurement to be subtracted to the pattern, above the cutting line.

• From this new reference point, draw an axis parallel to the cut line of the pattern.

  

• Glue the bottom part of the pattern to the top part, aligning the cut line and the axis drawn previously. Check that all parts are still perpendicular to the straight thread and to the front and back middles (if the pieces have them).

  

 

 

For a longer or shorter pattern

 

• Draw the sides in a straight or curved line according to the original pattern.

  

Check that the assembly lines between the different parts match perfectly and that there are no offsets.

 

Method B The objective is to modify the size of the stocking in proportion to the desired modification.

Extend/shorten the bottom of the sewing pattern in line with the existing layout. 

Case studies

It is best to use this technique sparingly so as not to alter the ease of a room.
Shortened hindered line
The fullness is increased on the bottom.

Extended Tied Line
The width is reduced on the bottom.


Shortened flared line
The width is reduced on the bottom.

Extended flared line
The fullness is increased on the bottom.


Shortened straight line
The scale remains unchanged.

Extended straight line
The scale remains unchanged.

 

 

How to make a pattern longer

 

• First, check that there is enough paper underneath the parts to be modified so as not to run out of space.

• Using a ruler and a criterion, transfer the value to be added below the hemline of the pieces concerned. Repeat this operation several times at regular intervals.

   

• Join all these points by drawing a line. To do this, it is advisable to use a modeler's ruler called a "parrot" to draw the curved lines. This operation can also be done freehand, provided that you have transferred a large number of markers.

 

• Extend the lines of the 2 sides of the new pattern, without changing their inclination. Make sure that the intersection between the side lines and the hemline forms a right angle.

• Check that the assembly lines between the different parts match perfectly and that there are no offsets.

 

How to shorten a pattern

 

• Using a ruler and a criterion, transfer the value to be subtracted above the hemline of the pieces concerned. Repeat this operation several times at regular intervals.

• Join all these points by drawing a line. To do this, it is advisable to use a modeler's ruler called a "parrot" to draw the curved lines. This operation can also be done freehand, provided that you have transferred a large number of markers.

• Check that the intersection of the side lines and the new hemline forms a right angle.