Silkscreening is a technique for getting designs onto paper, canvas, or cloth. One screen is used for each color, allowing complex designs to be made. For our purposes as needlepointers, we don’t have to be so complex; you can easily create designs with lots of impact using only a single color.
This post from Recycled Crafts at Craft Gossip points you to three different and easy ways to do this. It will point you to more detailed tutorials.
Just remember, when looking for images to use as needlepoint, look for images without lots of detail. That’s because needlepoint canvas has more hole than thread, causing most details to be lost. It’s best to choose simple designs that will have lots of impact when stitched, like the ones in the picture above.