Before we start, let's define what we mean when we talk about items. An item is anything that can appear within in your Paper.js project: layers, paths, compound-paths, groups, text items, rasters etc.
Every kind of item has specific behaviours: a path contains points, a layer can be active, groups and compound paths have children.
But since they are all items, they also share a number of behaviours. All these shared behaviours can be found in the Item reference.
Creating New Items
When you set item.visible to false, the item will be hidden and won't be drawn.
For example let's create a path and hide it. When you execute the following code, you won't see the item:
The following example create a circle shaped path, clones it and then changes a couple of properties of the clone.
When you select items or path segment points & handles in your code, Paper.js draws the visual outlines of them on top of your project. This is very useful for debugging, as it allows you to see the construction of paths, position of path curves, individual segment points and bounding boxes of symbol and raster items:
Blend Mode & Opacity
To make an item transparent, set its item.opacity property to a value between 0 and 1:
To change the blend mode of an item we pass a string to its item.blendMode property:
Visit the item.blendMode reference to see the different supported blend modes.