How to Draft a Pattern

Patterns are made from many materials, for many purposes. Here are two ways to draft a pattern like those used to cut out seat cover components

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• 1/4 inch plywood or 1/4 plexiglass
• Exacto Knife or razor blade knife, or Olfa cutter
• Scissors
• Weights
• Straight edge or yardstick
• gel writer or sharpie marker

1. In order to reproduce an item a single time, you can use the original as a pattern if you disassemble it: Label & mark so that you know how it goes together, before removing all stitching. Mark all the separate pieces with your "witness marks." Flatten your original with weights, and make them heavy enough to hold the original in place, while you trace it onto your new material. Cut the new pieces out with scissors and sew them using your witness marks for reference. Marker can bleed through! If marking your new fabric, use only margins that will be hidden once the seams are sewn up. Big clips help keep pattern pieces and the replacement together.

2. To make durable patterns that can be used multiple times, trace the original onto thin Plexiglas or plywood. Smooth curves and use a ruler to straighten and perfect the lines before cutting out your pattern with a jigsaw. A Roto Zip tool cuts Plexiglas better than a jigsaw. Sand wood with 180 grit paper and sand Plexiglas only on the edges with fine paper. Use super glue to add a handle to the topside of Plexiglas patterns, and staple a handle made from elastic or vinyl to wood patterns, or use small screws to hold a screen door handle on. Keep fingers well back from the edge while cutting! Test the accuracy of your pattern by assembling a duplicate made from it, to trial fit it.

3. To draft a pattern to cut items out directly, mount steel die rule on a wood block, using sponge release blocks on either side of the cut line, after tracing the outline carefully from the original. This is called pattern cutting, steel die stamping or die cutting. The pattern is perfected by micro measuring or is generated on a computer. I worked in a box factory where this technique was used to cut out everything from ice cream cartons to engine bearing boxes. Thousands of cuts can be made with a die mounted in a press, through multiple layers of material.

4. Patterns for oddly shaped items or things that are rounded after assembling present a unique challenge for the drafter, often requiring multiple adjustments and trial fittings. French curve templates and drafting supplies help greatly, including angle guides, see through grids and see through templates with various sized holes. The pattern is traced onto paper, perfected and then made from a dimensionally stable and suitable material, appropriate for the task.

[FrazzledNanny]

on 1/14/2009 Great details. Thanks for the article. 5*s