Jasper Expression Sheet

These are awesome! Expressions and consistency in a person is something I struggle with. I think they all look like the same guy, the only two that might be off are 2 and 3 on the top just because of the heavier eyelid. I do like it in the annoyed one toward the bottom though. I prefer with hairline, even if it is just an inkling of one like you did in some of them.

It's really good! I would suggest toying with darkening the eyebrows or maybe doing like a hatching thing. You don't have to take this advice but I think it will help your drawing. As far as hairline I think both having one and not looks good so you may want to do it based on how you think it looks. Try with and without and see what you like about both. I just want you to know that you draw really well and I like how you try to change and make your drawing better!

Those look very consistent to me, i can see perfectly it's the same character. About the bottom one, you could inclinate a bit more his eyebrows and make the eyes even sharper, that would give him a bit more of angryness, very good!

I feel like Jasper looks pretty darn consistent. However, and this is a bit nitpickly/personal preference, but I think their eyelashes get a little too thick when closed or half lidded making them look almost like different eyes. Maybe something around 5/6 or 7/8 of the thickness there would help. But again, I'm not absolutely sure about that.

Regarding the hairline, I feel like either way works, but I think you hgave the beginnings of something strong with the second row's surprised/anxious expression. What I'm talking about is that one little line right where the hairline would be. I think experimenting with a light implication of one or two lines for the hairline could help strike a strong in-between for both options, leaning a little more on the no hairline side of things.

Finally with the angry, I think it could be one or a combo of a few things that you may be seeing.

First, the hairline somewhat thins the overall hair shape because of its angle.

Second, the teeth seem to stop a little short based on the overall head shape and angle.

And third, the lines for the top of the eyes extend out, I think, just s smidgen too far (especially since the right eye blends into the hair a little bit).

But these are just what I think. I hope this helps, and feel free to discard whatever you think is wrong.

Regarding the hairline - I will challeng you to think about it like this
In a style like this the size of the eys, and overall shape of the head becomes somewhat fluid as the expression changes. Look at how the line of the jaw changes as you change the position of the mouth. This is not a bad thing at all, it is part of how this kind of art works.

And when you are doing something that is as minimalist as a cartoon face every single line that is involved is important and can totally change the entire expression.

A line on the forhead can take an expression from nuetral to angry, a line by the mouth can make it a smile or a smirk.

When you take away the hairline then the eyebrows take on more importance and you are less distracted from them. So when the figure is looking up with surprise the lack of hairline draws the eye upward and there is a simplicity to the face that is good.

Now look at the face where they are angry the hairline helps draw the eye down and adds to the weight of the image.

The point is that the hairline or lack thereof directs the eye to where you want the eye to go, and gives you more information.

So do not try and keep it there all the time, if the hairline interferes with the expression you are trying to create.