Is it possible to draw a line thinner than one pixel?

[Rich54]

I think I already know the answer to this question – it can’t be done – but I’ll ask anyway:

Suppose you want to draw a thin, wispy strand of hair on a fairly low-resolution photo. Because of the low-res, setting the brush tool to its smallest size (one pixel) results in a line that is still too thick. Is there any trick to get around this—to somehow draw a line thinner than one pixel? I’ve tried drawing a line and then making it thinner using Transform>Scale, but that doesn’t work. I’ve also tried drawing a one-pixel line in a separate, high-resolution file and then importing that line into the low-res file, but that doesn’t work either.

Any ideas?

 

[MrToM]

...I think I already know the answer to this question – it can’t be done...

Nuff said.

Regards.
MrTom.

PS.
PS will allow you to place a guide ON a pixel,(As opposed to between them), effectively splitting it, so Adobe think its possible....but no.

 

[ALB68]

I would think that PS being a bitmap based program would require at least 1 pixel. If you zoom in really close you will see that PS images are built of 1 pixel blocks, so I don't think it would be possible.

 

[Rich54]

Ok, that's what I thought. Thanks anyway.

 

[ALB68]

Ok, that's what I thought. Thanks anyway.

If I draw a 1 pixel line in a 72ppi image with the brush tool and zoom in as close as possible , it looks like it's actually 2 pixels. Try the pen tool as a shape with a very low point size for the stroke with no fill. That looks to be thinner than the paint tool,

 

[MrToM]

One option you do have though is to re-sample the image.

Its not ideal but re-sampling up by a factor of 2 would give you twice the pixels to work with, as in width and height but the downside to that is you would have to keep it that way. Once you had drawn your 'hair' you couldn't then re-sample it back down to its original size....for the same reasons you've discovered with your other methods.

There are after all only so many pixels in an image.......a 1px line re-sampled down by any factor would simply diminish into the surrounding pixels....it may still be visible but not as clear as having a whole pixel to denote it.

Imagine a vertical column of red pixels, and one next to it of black.
If you re-sample down by 2 then just 1 vertical column of pixels has to denote both red and black.....this can't happen of course but a compromise would be a column of pixels that were a mix of the two....a kind of dark red.

This would give the impression that both red and black still exist but not as before....the red being darker and the black being lighter.
How these pixels mix is down to the interpolation used when re-sampling but its still not ideal in any case.

Not much else you can do really.

Regards.
MrTom.

 

[MrToM]

...If I draw a 1 pixel line in a 72ppi image with the brush tool and zoom in as close as possible , it looks like it's actually 2 pixels...

Well spotted Larry!

Strange it does that, is that another Adobe-ism? "The brush size is the diameter unless its 1px then its the radius"....genius.
Good old Adobe.....always keeping everyone guessing.

Try the pen tool as a shape with a very low point size for the stroke with no fill. That looks to be thinner than the paint tool,

You can set this to 1px and it works pretty well......any lower than 1px and it starts to become transparent.

I couldn't get the brush tool to be 100% opaque at 1px (2px) but if your going down that low you might as well use the pencil tool.
That will stay opaque down to 1px no problem.

Regards.
MrTom.