Many fashion designers have beautiful fashion croquis to show their designs, aesthetic, and render fabrications. While they look nice, and require a great amount of both time and artistic talent, a technical illustration is needed to communicate your design to your pattern maker and sewing contractor.
A technical drawing differs from a fashion croqui in that it shows a flat rendering of your design, and shows your pattern maker the relationships and proportions between style lines, placement of buttons and zippers, and even stitch types such as top stitching or flat felled seams. Often special seams will be annotated on the drawing.
Most technical drawings are created on the computer, using a program such as Adobe Illustrator. If you feel comfortable, you (the designer) can do this yourself, or you can hire an illustrator. Most companies will charge per illustration, rather than by the hour.
A good technical illustration, also called a "flat", will be a scale drawing of your design, both front and back view, and sometimes include detailed drawings of a particular piece, such as a unique pocket design or embroidery. Solid lines show seams, dotted or dashed lines show stitching. Flats are not usually colored in, especially when being used to show the design to your pattern maker, however some designers use flats in their line sheets to show buyers, and in this case it would be appropriate to show colors and prints if applicable. Flats are also utilized, and expanded upon in more detail in your specification package.
If your garment contains any unusual design features or requires specific sewing techniques, it is wise to also have illustrations made up to show these in detail. Along with a sewn sample, it will ensure that your sewing contractor understands what you expect your garment to look like. A side note, some sewing contractors will sew your first samples, others prefer that you or a sample maker do.
Once you have your illustration, front and back, you will use this on your patten card, construction notes, measurement chart (for grading), and often on your company's line sheets.
For questions or more information on technical illustrations for your company, please email Xochil.