best photo to stencil converter To use this online photo to sketch maker, first press the "Browse" button and then select an image. best photo to stencil converter Next press the "Upload" button to load your image. Now adjust the "Contrast" and "Density" by dragging the range sliders left or right. The "Contrast" adjust the threshold of the white and black pixels. As the slider is moved to the left, the background noise is minimized. The "Density" determines how the neighboring pixels are entwined or combined. Think of this as line thickness. Finally, when satisfied with your stencil, press the "Save" button to save your new sketch or pattern.