This tool will help you construct your own Ghost Pirates Captain cards without much in the way of fancy image editing software and art templates.
Ideally, your custom image will be an illustration with transparency sized at exactly 285 x 379 pixels, but it should work well with other sizes. There are even buttons to shift the image around to get the best fit.
You may use the paintings on the right to serve as background images to your illustration, if you're using an image that supports transparency (e.g. the PNG format) you'll be able to see the background past your illustration as per this sample image.
Printing at approximately 60% size should give you a poker card-sized print.
Please note that this app does not save your work. You can print your card or take a screenshot to keep a digital copy when you're finished.
When printing, make sure that printing backgrounds is turned ON, otherwise none of the images will print.