The most useful example in plugin documentation is often the smallest one that explains the contract. For PrinterPluginPro, that contract begins before the print call: the texture must contain accessible pixel data in a supported format. A beautiful image in the game view does not, by itself, satisfy that requirement.
I've put the PrinterPluginPro documentation into a public repository. It covers sending textures from Unity to a printer on PC and Mac, including single images and multiple textures in one document. The short examples are useful because they give an integrator a direct route to a first job, while the format requirement explains a common boundary in the workflow.
Begin with the pixels
The documentation requires an uncompressed 24-bit or 32-bit texture with read/write enabled. Those words distinguish an image that Unity can render from one whose pixel data is available to the printing path. Compression, import settings and GPU-only render targets can all change how an image is stored or accessed.
A RenderTexture is a natural place to compose an output image, but it isn't automatically the readable Texture2D used in a simple print example. A typical workflow renders the composition, reads the intended result into a suitable texture and then submits that texture. The capture step is application work; it shouldn't be confused with a promise that the print API accepts every kind of Unity graphics resource directly.
Timing matters. Reading before the camera has produced the intended frame can capture old or incomplete content. Reading at the wrong resolution can send a small preview to a large page. The application should define one clear moment at which the composition becomes the print artifact.
A useful test image would include a labeled top edge, a colored corner in each direction, a circle and text at several sizes. It makes several classes of error visible at once: rotation, mirroring, cropping, aspect ratio and inadequate resolution.
Fitting an image onto paper
The documented single-texture example uses FILL_PAGE. That is a layout choice, not a description of the source image. If the image and printable region have different aspect ratios, filling the region and preserving the complete image can conflict.
Consider a square portrait and a rectangular page. A fit operation can retain the full portrait with unused space around it. A fill operation can use the full region while cropping part of the portrait. Neither should surprise the person pressing the print button. The preview ought to show the selected policy and protect important content accordingly.
Multiple pages add ordering and consistency. If an application produces a sequence of textures, their order should be stable and their orientation intentional. A screen that shows page two while the print array still contains an older version is a state-management problem, even though the printer receives valid data.
The image resolution should follow the physical result. As an illustrative calculation, a 10 by 15 centimeter image at 300 pixels per inch needs roughly 1,181 by 1,772 pixels. That doesn't guarantee a particular printer's quality, but it gives the application a sensible source-resolution target. A display preview can be much smaller while sharing the same layout.
The job continues outside Unity
Once a job reaches the operating system's print system, the application no longer controls every part of its journey. A queue may pause, a device may be offline or the wrong paper may be loaded. The interface should distinguish submission from physical completion and make repeated clicks difficult to confuse with a request for extra copies.
For an installation, I would also keep the completed composition until the user has a clear way to retry or leave. Returning immediately to a blank start screen can make a printer problem feel like lost creative work. The image is inexpensive to preserve compared with the effort the person may have put into making it.
That is the division I want the documentation to make clear: provide a direct print operation and explain the data it needs. The application still owns composition, capture timing and the visitor's experience around the job. Making that division legible is what lets a native feature become a reusable Unity component.