The technical sketch, bill of materials, and trim sheet

The tech pack for each style number consists of a technical sketch with details, bill of materials and trim sheet, construction specifications, point of measure and size specifications, and supplemental pages for prototype development, labels, folding, and packaging. Let’s examine each of these.

The technical sketch

The technical sketch (also called a flat sketch or flat) is a line drawing of the fashion product.

The design brief may have included an illustration of the garment. From this illustration, a technical sketch is created. The process of creating the technical sketch may start with a hand illustration or may start with a computer-aided design (CAD) or graphic design system. Some designers believe that sketching on a computer stifles their creativity and therefore, they prefer to “think” with pencil in hand.

Designer’s hand illustration of a garment.

Technical sketch created using CAD of the same garment.

• New garment designs are drawn by using true proportions from a croqui (outlined sketch of a model) stored in the system.
• Some software programs provide a style library of basic garment silhouettes, such as shirts and pants, as well as garment components, such as collar and pocket styles. The designer creates the new style by bringing the desired components together.

• placement and spacing of buttons or pockets
• any edge stitching or topstitching
• spacing between pleats or tucks
• findings, such as the number, size, and style of buttons; zipper length, color, and style; snaps and buckles
• pocketing, lining fabric, and interfacings.

Design details specified on a technical sketch.

Bill of materials and trim sheet

Bill of materials for a tech pack.

Although the tech pack and these pages relate to one product, the materials and trims selected may be used in numerous style numbers.

The bill of material and trim sheets are descriptions of the construction components for the product (fabric, thread, trim, linings, labels, hangtags, etc.) including:

• fiber content
• weave or knit structure or other material description
• vendor or supplier
• placement of trims, labels, hangtags, etc. on the garment
• width of fabric or size of trim
• quantity of materials and trims
• cost.

Having covered the technical sketch and bill of materials and trim sheet, let’s move on to the next part of the technical pack.