Block patterns and Style Patterns - I often hear my clients using these two terms interchangeably when referring to the pattern that has created their garment. I’ve also heard it referred to as “my block style pattern”. This can be confusing for any one working with patterns, or anyone at all I suppose! Let me help clarify as these are two very different things…
A block pattern is the most basic shell of a garment and it is meant to be used to cut & sew in the actual final fabric quality. There are typically no buttons, zippers, pockets, flare, bells, or whistles. It is the basic silhouette from which individual styles are created. In corporate offices where I’ve previously worked, blocks are a huge, important project as they are the fit foundation to everything else a designer comes up with. Blocks enable the fit of a garment to be consistent within a fabric quality and thereby create a happy customer in the end. Blocks are helpful because people can review the drape of the fabric and the fit of the garment on a form or body, without getting distracted by the details, like ruffles or pleating for example. They ultimately make everyone’s life much easier throughout the creative fashion process. They are the base from which all other style patterns are made. See Photo 1 above for a basic sheath dress block example. Let’s call this BLOCK1. (Back in the day, my teacher in fashion school referred to these as a ‘basic sloper’, so you may hear that depending on who you speak with.)
The style pattern is the actual pattern used to cut & sew a garment specific to one style only, with all design details included. It is possible to have only a couple of block fits in a seasonal collection, but there needs to be a style pattern for every individual style. See Photo 2 below for a style pattern example. This pattern was based on Photo 1 / BLOCK1 using the same fabric quality. The measurements are maintained to keep the fit consistent, but the neckline is changed to a boat neck and style lines are added to create sewn in diagonal stripes. This is now transformed into a pattern I'll call STYLE1. BLOCK1 can then be used again and again to create new designs within a same fabric quality while maintaining a signature fit for a brand or collection. If a new or different fabric quality is desired, then go back to block making and perfect the fit in that new quality. If the same pattern or block is used to trace, cut, and sew five totally different fabric qualities without being adjusted to accommodate the stretch, weight, and drape of those fabrics, then the odds of those final garments fitting well on a person is slim. New fabric = new block pattern, then new style pattern.
This is a brief explanation based on one sheath dress in a woven fabric. If you have any further specific questions, please send me an email using the link at the top of the page or the contact form on my home page. Thanks! (Images from Patternmaking for Fashion Design by Helen Joseph Armstrong, 2nd edition)