Guide Overview
The Seamly2D Reference Manual is a comprehensive guide for using Seamly2D, a free open-source patternmaking software for fashion designers and patternmakers. This software helps create precise sewing patterns that can be automatically resized based on measurements.
Key Insight: Seamly2D works together with SeamlyME (measurement editor) to create custom-fitted patterns. The software uses formulas and measurements to generate patterns that automatically adjust when measurements change, making it ideal for creating multi-size patterns.
Key Features
Key Software Capabilities
Formula-Based Pattern Creation
Seamly2D uses mathematical formulas to define pattern segments, allowing for precise control and automatic resizing when measurements change. Formulas can include measurements, constants, operators, and trigonometric functions.
Comprehensive Measurement System
Works with SeamlyME to manage individual and multisize measurements. Patterns automatically adjust when measurements are updated, saving significant time in pattern adaptation.
Advanced Drawing Tools
Includes specialized tools for points, lines, curves, arcs, and operations like rotation and flipping. The software supports complex pattern manipulations needed for professional patternmaking.
Detail and Layout Creation
Complete workflow from drawing to final pattern layout. Includes tools for adding seam allowances, labels, grainlines, and preparing patterns for printing or cutting.
Multi-Format Export
Export patterns in various formats including SVG, PDF, DXF, and more. Supports tiled PDF printing for large patterns on standard printers.
True Dart Tool
Specialized tool for creating accurate darts that account for fabric shift when sewing, ensuring proper alignment in the finished garment.
Content Overview
Document Contents
Formulas and Formula Wizard
Seamly2D uses formulas to set segment lengths and angles. Formulas can contain:
- Constants (integers or decimal numbers)
- Variables from measurement tables
- Operators: +, -, *, /, ^ (power)
- Algebraic and trigonometric functions: sin, cos, min, max, avg, fmod, pi
- Conditional statements: ((a operation b) ? c : d)
The Formula Wizard simplifies formula creation by listing available variables. For length calculations, you might use formulas like: waist_circ / pi to find waist diameter.
Angle Specification: Angles are specified in degrees, where 0 degrees points East and values increase counter-clockwise. This follows standard mathematical convention for angles.
User Interface
The Seamly2D interface is organized into several key areas:
Title Bar
Shows current file name, measurements file, and program name.
Menu Bar
File, Pattern piece, Mode, Measurements, History, Window, Help.
Easy Access Tools
Quick access to common functions like New, Open, Save, Sync.
Tools Panel
Left-side panel with all drawing and editing tools.
Drawing Board
Central area where patterns are created and viewed.
Tool Options
Right-side panel with options for selected tools.
The three main modes are Draw (creating patterns), Details (defining pattern pieces), and Layout (arranging pieces for printing).
Drawing Tools Overview
Seamly2D provides a comprehensive set of tools for pattern creation:
Point Tools
11 different point creation methods including distance and angle, along line, perpendicular, bisector, and intersection tools.
Line Tools
Create straight lines between points or find intersections.
Curve Tools
7 curve creation methods including simple curves, curved paths, and specialized curve tools.
Arc Tools
Create arcs with specific radii and angles, find intersections.
Elliptical Arc
Create elliptical arcs with two different radii.
Operations
Group, rotate, flip, move objects, and create true darts.
Point Tools
Point tools create reference points that form the foundation of your pattern:
- Point at Distance and Angle: Creates a point at specified distance and angle from another point.
- Point at Distance Along Line: Places a point at a specific distance along a line between two points.
- Point Along Perpendicular: Creates a point at a 90° angle (or other specified angle) from a line.
- Point Along Bisector: Places a point along the angle bisector between three points.
- Special Point on Shoulder: Specialized tool for shoulder point placement considering dart width.
- Point at Intersection: Finds intersections between arcs and lines or between two arcs.
Operations Tools
Operations tools allow complex manipulations of pattern elements:
- Create New Group: Group multiple points and lines for easier management.
- Rotate Objects: Rotate selected points and curves around a pivot point.
- Flipping Objects: Mirror objects across a line or axis.
- Move Objects: Move selected objects by specified distance and angle.
- True Darts: Create darts that account for fabric shift when sewing.
True Dart Tool: This specialized tool adjusts dart points to ensure proper alignment in the finished garment. When you sew a dart, the edges shift, and this tool compensates for that shift so the seam lines up correctly after sewing.
Detail Tools
Detail tools transform your drawing into actual pattern pieces:
- Seam Allowance Tool: Creates the basic outline of a pattern piece.
- Union Tool: Joins two pattern pieces into one.
- Piece Path Tool: Adds internal paths or custom seam allowances.
- Pin Tool: Places pins for label placement.
- Insert Node Tool: Adds missed nodes to existing details.
Detail options allow you to customize seam allowances, add labels, grainlines, and passmarks to your pattern pieces.
Layout Creation
The Layout feature arranges your pattern pieces for printing or cutting:
- Background Size: Can be pre-defined paper sizes, roll paper, or custom sizes.
- Multi-sheet Layouts: Created when all pieces don't fit on one sheet.
- Tiled PDF: Option to print large layouts across multiple standard pages.
- Export Formats: SVG, PDF, PNG, JPEG, HPGL, EPS, PS, DXF.
Layouts don't include internal hatch marks, points, or point labels - only the final pattern pieces as they appear in Detail Mode.
Keyboard Shortcuts
Seamly2D includes various keyboard shortcuts to speed up workflow:
New file
Ctrl+N
Save
Ctrl+S
New pattern piece
Ctrl+Shift+N
Zoom in/out
Ctrl+ +/-
Undo/Redo
Ctrl+Z / Ctrl+Shift+Z
Table of variables
Ctrl+T
Mouse shortcuts include Ctrl+Scroll to zoom and Middle mouse button to drag/pan the drawing area.
Patternmaking References
The manual includes references to recommended patternmaking resources:
- Books: Works by Winifred Aldrich, Natalie Bray, Bunka Fashion College, Helen Joseph-Armstrong, and others.
- Online Instruction: Free resources including Leena's Pattern Drafting Lessons and Don McCunn's pattern design guides.
These resources provide the foundational knowledge needed for patternmaking that Seamly2D helps implement digitally.
Note: This is a summary of the complete Seamly2D Reference Manual. For detailed instructions, tool explanations, and visual examples, we recommend downloading the full PDF guide.