Is the difference also there if you compare the two images as View > Actual Pixels in Photoshop?

So when you view the layered psd at Actual Pixels it is »identical« to the jpg?

That would mean that the difference you perceive at smaller magnifications is just a preview issue.

Just to humour me, could you please post a screenshot of both psd and jpg at Actual Pixels? (Edit: naturally of the same section)

And the Layers Panel for the psd?

Which one of the three points is checked?

What are your Color Settings (please just post a screenshot)?

Just one comment...  Your lines in your screen grab are NOT thinner, they are simply a good bit lighter.

You should try to use the proper terminology, because you will end up realizing, when C.Pfaffenbichler helps you get to the bottom of your problem, that you likely are experiencing a gamma/color-management issue causing your pixels to be displayed far more lightly in one case than another.

Besides your color settings in Photoshop, it will also be helpful to know what color profile is associated with your monitor at the operating system level.

-Noel

P.S., I don't know what result you're going for, but the JPEG with the darker lines looks a lot better on a calibrated display.  The screen grab seems too light.

Another land of the lost thread.

I mean that before the ill fated Photoshop 5, you could pretty much just use it, now you have to grasp the concepts.

Compliments to emil emil.

tashawaddell, have you set Photoshop’s Transparency Settings to display white instead of the default checkerboard pattern?

Apparently tashawaddell has his transparency settings set to None and his Open GL settings are set to Normal or Advanced. Then Photoshop simulates the transparency of the drawing which has a lot of semi-transparent pixels from the anti-aliasing. When the image is flatten this simulation is gone resulting in a unexpected surprise - darker image. And there is no automatic fix for this but to use the color correction tools like levels and curves or even adding an overall transparency of the layer to achieve the same look after adding an opaque layer at the bottom.

My apologies to tashawaddell if I my wording was wrong.

Some of the regulars here may have noticed that I'm struggling with my ESL, I often edit my messages a lot because of that but when I'm in a rush I'm at my worst, I'm trying to improve though