How to enlarge a pattern in a non-existent size

There is nothing more frustrating than realizing that a pattern is not offered in its own size. We will see here that solutions exist in order to enlarge the pattern in a reasoned way. Because be careful, the gradation is normally carried out according to a very detailed measurement table, including enlargement values ​​specific to each type of clothing but also morphology. This technique can be used to enlarge a pattern by one size or two, but beyond that, there is a risk that the pattern will no longer conform to the statures. This is also the case when you want to transform a pattern into a very large size.

Principle of gradation

Grading is the job of a grader or pattern maker.

A clothing pattern is built in a well-defined size, such as 36 or 38. It is on this basis that the grading will then be carried out. It is then necessary to refer to European standards and very detailed measurement tables to calculate the necessary enlargements between 2 sizes. The measurements to be reported take into account vertical values ​​as well as horizontal values.

Examples of scenarios

Example 1

A pattern is offered from 36 to 46 while the desired size corresponds to a 34 or 48. A gradation is possible on all the pieces of the pattern.

Example 2

A pattern is offered from 34 to 48 while the desired size corresponds to a 54.
A gradation is not recommended because the difference with the last proposed size is too great.

Transformation

Use a graduated ruler to extend the lines, a set square to draw perpendicular lines, and a parrot (a model maker's ruler with a curved shape) to draw curves.

• Check that all pattern pieces have been selected.

• The goal of the exercise is to connect the different sizes of the pattern with a straight line at specific locations on the outline. This rule must therefore be applied to each intersection between two lines forming an angle, but also at each assembly mark.

• Once the lines are drawn, check that they extend beyond the first and last size.

• Measure the distance between two points of intersection. This distance should normally be regular and repeat between each size. 

• If the goal is to enlarge the pattern by one size, carry this measurement beyond the last size, to the outside of the piece.

  If the goal is to reduce the pattern by one size, transfer this measurement just before the first size, to the inside of the piece.

• Once all the reports have been made, connect the new points together according to the same path as for the other sizes. That is to say, you must respect the straight lines and curves in order to preserve the cut of the model.

• When all the pieces have been graded, check that all the lines fit together perfectly. If a mismatch is found, it is very possible that there is an error in the grading.