UserManual:Creating Layouts

From Seamly

Before you will be able to export or print pattern you should create a layout. Seamly2D supports the automatic creation of layouts. The most common mistake users do is to think that a layout creation has something to do with printing. No, printing (and export) is separate steps that proceed after you create a layout.

Seamly2D's Layout generator was not designed to create a fabric layout. It doesn't obey grainline. Right now you can use it only for preparing workpieces for export or printing.

Creating really powerful layout generator is hard task. The main goal of current implementation is to allow you work with pattern and quickly export your result. It was design to quickly create a valid layout using your PC power. Very often a layout will be far from optimal for you. But if you are not satisfied with automatically generated layout you always can export it in SVG (or any other vector based formats) and rearrange workpieces as you need.

To create a layout you must pass at least one workpiece to Layout generator. If you have at least one workpiece, but still can't start creating because Seamly2D doesn't see any please check if at least one is selected in section Group. This section control which workpieces will be passed to Layout generator the next time. To begin creating switch to the Layout mode. If there is no previously rendered layout then Seamly2D will automatically show you a dialog with options.

Layout options[edit | edit source]

A picture of the Layout options dialog.

Paper format[edit | edit source]

This has a dropdown box from which you can choose the paper dimensions used by the Layout generator. As was mentioned previously this has nothing to do with your printer or plotter capabilities. The Layout generator will fail to create a layout if at least one workpiece can't be arranged.


The common recommendation in this case is to select a paper size big enough to arrange the biggest pattern piece in the pattern.

A words about the predefined options you can find in the dropdown list: Seamly2D exports data with resolution 96 dpi. You should take into account this value if want to export a pattern image and continue to work with it. If you cannot find a usable size from the list of templates, switch to Custom and edit the size manually. Note. The first time you switch to Custom size, Seamly2D will continue to use the previous size values until you manually change them. The fields labeled "Width" and "Height" are used to edit your custom size. Also you can choose between portrait or landscape layouts.

*Of note: The maximum height you may select is limited to 866.986 cm. This is because of compatibility with certain exporting formats.

When you want print your layout later you should also take care of printer margins.


Seamly2D will show you all printers it can find on your PC and retrieve minimal margin fields required by selected printer, you can also customize them. The wider your printer margins, the less room will be left for the Layout generator to find space for the pattern pieces.

The margin fields use the same measurement units as was set for the paper size.

Check option Ignore margins if you don't want to take printer margins into account.

Layout options[edit | edit source]

This is the second most important part of the Layout generator after paper size. To effectively use it you should have some understanding how the Layout generator works. So, let's see which options do we have and how to effectively use them.

  • Gap Width - distance between workpieces on layout. Imagine this as additional layout allowance around a workpiece. So, actual distance between workpieces will be twice bigger than the gap width. If you don't use an automatic seam allowance at least check if it is correct. If it is not Seamly2D will create incorrect layout allowance and thus will produce an incorrect layout.
  • Shift/Offset length - very important option that controls how accurate will work the Layout generator. The algorithm sees any workpiece as list of nodes. Any two nodes create an edge. Because it uses only vertices of edge as control positions sometime this is not enough. This option says how long should be an edge before it will be cutted on pieces. This process creates more positions to check and in some cases this make result better. But this also dramatically increase number of positions to check and make process of arrangement longer.
  • Save length of the sheet - use this option if you prefer saving length of paper sheet. This is especially useful in case of roll paper format.
  • Rotate workpiece - help avoid situations with workpieces that have convex shape. Those shapes can't be handled by basic algorithm. Rotation value sets angle value for single workpiece rotation around vertex point. For example: 180 means two rotations by 180 degree each. Numbers of rotations can be calculated from the expression 360/angle_valueWarning. Increasing rotation number will increase time for searching best position for workpiece.
  • Rules for choosing the next workpiece - there are three possible strategies selecting workpieces for arrangement: three groups: big, middle, small; two groups: big, small and descending area. Seamly2D will calculate area of each workpiece and arrange them according to selected strategy.
  • Auto crop unused length - select if you need to crop unused length of paper sheet. Usually used in combination with option Unite pages.
  • Unite pages (if possible) - unite all pages in one if possible. Use it if you want to get one paper sheet from many smaller. The max length is restricted to max 32768 px.
  • Divide into strips - enable for sheets that has big height. Because the algorithm was designed to work with rather regular formats like A0, A1, A2 etc. it will work very slow for sheets that has big length. To speed up arrangement this option will cut sheet on strips. Select multiplier to select how long will be a stripe. The multiplier take height of the biggest workpiece to calc the actual stripe length.