How to make a round halftone texture/pattern to use? I tried to do this via Bitmap, but it doesn't make exactly what I want. Thanks for your answers!
There's already answered how to create a halftoning pattern which simulates BW printing It uses round dots. Just in case you want square or other custom pattern, I can add a little.
See the following image:
At left there's an yellow circle which is shaded with a gradient layer to resemble a ball.
In the right image the shading is halftoned with square dots, there's used 8 different shading levels. The yellow circle layer is the same in both.
In the following image you see the basic layering. The canvas is 1000 pixels wide. The circles are moved temporarily a little apart to see them separately.
Blending mode multiply is not dependent on the order of the layers. Thus the solid yellow circle can well be on the top and have blending mode = Multiply. This gives a possiblity to work with adjustment layers to create the halftoning and the adjustment layers do not affect to the yellow layer.
At first we create the custom halftoning pattern. I have prepared 2x2 pixel checkerboard pattern ready to use with the pattern brush. See Note1 on how to create it.
We want 8 halftoned greyshades, so we fill a rectangle = 1/7th of the canvas dimensions (=14,3%) with the checkerboard. 7 means 7 steps, which results 8 levels like in the stairs. It's in a new layer "Square raster" just below the yellow circle.
The filled area is at the top left corner. The same screenshot shows a high zoom snippet of the checkerboard pattern. All dots are single pixels. (see NOTE1 how the checkerboard pattern is done)
Next we drag the checkerboard pattern to full canvas size. Photoshop nicely blurs the pattern and we have evenly spaced greyshades between black and white. Here's a high zoom image of the stretched pattern:
Next we select the emptiness around the yellow circle and delete the unnecessary area of the halftone pattern in layer Square raster. That layer gets blending mode = Add. We see that the sum with the gradient is all white at the white end of the gradient and nearly all less than white at the black end of the gradient.
The halftoning is resulted when we treshold the sum just below full white. We could use Image > Adjustments > Treshold, but it needs merging the raster and gradient layers. We can be non-destructive by adding a curves layer and dragging the curve vertical near the bright end:
As we see, the result isn't especially smooth. The spacing of the levels isn't even. I cannot prove it mathematically, but this is a result of having all made of pixels not much smaller than the dots and without antialiasing. We can fix it by allowing a little grey with a less steep curve:
Another way is to use "dithering". We can add noise to the gradient layer or simply paint very thin random pattern onto it with low opacity black or white or both. Allowing a little grey with the curves is the fastest way and at least for me good enough.
NOTE1: How to make the checkerboard
- start a new image 2x2 pixels
- with the pencil tool paint the pixels black and white
- select all
- goto Edit > Define Pattern, OK