Photoshop Path ToolsIf you haven't used Illustrator, FlexiSign, or LXi graphic design software, you may be wondering what a path tool is. Vector paths are simple shapes composed of points or nodes and the lines that connect them. All vinyl graphics made with cutting plotters rely on vector art. The plotter blades follows the path defined in the software. Click here for a more in-depth explanation of the difference between vector and raster artwork. As the name implies, Photoshop is used primarily as a raster photo editing application and is not suitable for creating vinyl graphics. But it's also used in lots of graphic design applications beyond airbrushing blemishes off of fashion models, so there are path and shape tools tucked away in the toolboxes. Because they define shapes with clean crisp edges, they're handy for precise extraction of foreground images from their background elements. Extracting raster elements with the path tool often requires using the tools to create a clipping path that can then be used to delete background pixels.
Fig 1: Here is the clipping path for our OKI WT sample. Like layers, you can name the path when you save it.Clipping paths are also essential in the design of T-shirt transfers because they tell the OKI WT printer where to put the white toner (Fig 1). For step-by-step instructions on how that works, please click here to view or download the tutorial. The tutorial describes how to start with a full color raster image and select the CMY values you want to print, then convert those extracted pixels into a clipping path. It works, but there is a downside. You are essentially vectorizing a raster image. This is a process well known to vinyl sign makers because. As the aforementioned raster and vector article explains, vectorizing a raster image may require you to fine tune the resulting vector image to eliminate excess points and smooth out the paths. The same is true when you convert a raster layer to a path in Photoshop. The resulting clipping path may not be as precise as you want. The more precise your clipping path is, the better the registration will be between the CMY layer and the white underbase. So you may need to use the Direct Selection Tool to move, add, or subtract points to fine tune the path before it's usable as a white layer. The problem with this process is the fact that you're building your design from the top down. That can be an inefficient and cumbersome work flow.
Path Tools for Better DesignIn addition to defining your white layer, the path tools in Photoshop can add distinctive elements to your design that make the most of the self-weeding characteristics of the laser transfer process. One of the advantages of laser transfer vs print and cut is the ability to create opaque images on dark garments without having to weed printed and cut heat transfer film. If you have to spend an hour optimizing your clipping path to create the white underbase for an intricate design, you're just trading time spent weeding for time spent designing.
Fig 3: The original shapes and symbols have been duplicated as raster layers and colored. Then they were merged into a single shape, designated underbase. Ready to print.Adding multiple symbols creates separate layers. These all need to be on one layer to serve as a single clipping path for an effective white underbase. This can be done by using the Path Selection tool. Paths can be copied and pasted in the Paths toolbox. Or you can just select the shape layers in the layers toolbox and merge them into one shape. The convert the shape to a clipping path and you have your white layer ready for printing. Tip. Once your design is done, you may find you need to resize, rotate, or move the CMY layer. If you do this without linking it to the clipping path, you'll ruin the registration of the CMY and white layers and cause some interesting printing problems. Since the white layer has been saved as a clipping path, it will actually clip the top layer and cut off any CMY elements outside the path. Those areas won't print. If you've forgotten that the path is out of alignment, this can cause quite a bit of head-scratching. WWW.SignWarehouse.com