This tutorial was created using Photoshop 6. However, by converting some of the quick-keys and menu items mentioned, it can be made to work in any version of Photoshop. You should also be somewhat familiar with creating Paths before attempting this tutorial.
This is not a beginner's tutorial. But feel free to try it if you like.
Ok lets start by creating a New Document (Ctrl/Cmd+n). The dimensions will be 320w x 420h -- pixels, the Resolution should be 72, the Mode should be RGB, and our document should have a White Background.
If you like, you can go ahead now and import/insert/or create your own textured background image -- like I have here with the marble texture as my background. It's not essential to do this now though, so if you have nothing specific in mind for a background, you can just wait and do this at the end.
1. Create our basic paper shape using Paths.
Ok so to start off we'll need to create a preliminary paper shape. After that, we'll fold one of the corners over. This part is where some people get confused -- they try to work out a way to create the paper with it's corner already folded. It's actually much easier to just create a normal paper shape first, then work on the folded corner afterward.
Create a new layer, and name the layer paper.
PS 6 or newer users, do the following: ( Anyone with an older version of PS, skip down to 'PS 4/5+ users'. )
Choose the rectangular Vector Shapes tool from the Toolbar.
Then select this icon from the Options Bar -- "Create New Work path":
Now drag out a long rectangular shape -- like a normal piece of paper. Leave some space around the outer edges, so our background can still be seen a bit. Leave a bit more space than what you see in my header image at the top of the page.
Now open the Paths palette. Continue on with Step 2, below.
PS 4/5+ users, do the following:
Use the Rectangle selection tool to create a long rectangular shape -- like a normal piece of paper. Leave some space around the outer edges, so our background can still be seen a bit. Leave a bit more space than what you see in my header image at the top of the page.
Now open the Paths palette.
At the bottom of the palette, click on the "Make Work path from Selection" icon ( the circle with the handles on it ). This should change your selection into a rectangular path.
2. Modifying shape
Choose the Pen tool 
from the toolbar.
Hold down the Ctrl/Cmd key, and click anywhere on the Path. As you hold that key down, you'll see that the pen tool changes into a selection arrow tool. From now on, you'll use this method to select the control points of your Path. Let go of the key now, and the cursor changes back to the previous tool.
Now picture in your mind how you want your paper fold to look -- how far up will the curl go, and how much will the bottom curl up? Once you've decided this, move on to the next page.
If you're confused after reading this page, then watch this Quick-View Image Sequence to help make things clearer:
1: draw paper shape path with the Vector Shape tool.
2: choose the Pen Tool, then hold the Alt/Option key down with your mouse over the bottom right control point; as shown.
3: click and drag to add curve handles.
4: move corner control point up and inward, and position curve handles; as shown.
5: right-click (MAC: long-click) and choose "Fill Path" from the option menu.
6: the filled paper shape.
7: draw a small square, using the Vector Shape tool. Match the corners to the curl line; as shown!
8: delete the bottom right corner control point.
9: right-click (MAC: long-click) and choose "Fill Path/Sub path" from the option menu.
10: the filled corner curl shape.
11: add a Linear Gradient; as shown here -- top to bottom.
12: add a Linear Gradient; as shown here -- bottom to top.
13: create a New Layer just above the document Background, and draw a shadow shape path by using the PEN tool, and tracing the paper shape; as shown.
14: reshape the shadow Path for the correct effect; as shown. Then right-click (MAC: long-click) within the Path area and choose "Fill Path/Sub path" from the pop-out menu.
15: once it's filled, Gaussian Blur the shadow and lower the Opacity to 35%.
3. Curling our paper corner (1)
This part is pretty simple. Have a look at this example image and you'll notice I've drawn a red arrow to show you how to make the corner of the path curl inward. First however, we need to add some bezier curve handles.
Make sure the Path is selected, then hover your mouse over the bottom-right control point. Now hold down the Alt/Option key -- you should notice your cursor changes to a half-outlined arrow head. Click and drag on the control point to drag out some curve handles.
Hold down the Ctrl/Cmd key so the selection arrow appears, then drag the corner control point up, and inward. The bottom and side edges of the path will automatically curl.
Remember, I warned you that you'd need to know how to use Paths. If you're unfamiliar or confused about this tool or these instructions, consult the Help files before continuing.
Tip: If you hold the Ctrl/Cmd and the Shift keys down at the same time as you drag the control points and curve handles, it will constrict your movement to perfect 90° and 45° angles. This can be helpful at times.
As my example shows, the paper will take on a natural bended look, just by you moving that one corner control point around. This is why I like doing this effect myself, and not with a plug-in. The plug-ins don't give you this kind of control.
And if you want even more control over the shape of the paper, you can add more control points, like I have in my example images. It's your effect, so the choice is completely up to you!
4. Curling our paper corner (2)
If you'd like to add some more curl to the bent corner of the paper, now's the time to make that edit. Select the corner control point we moved in toward the middle, and move its curve handles to make the sides coming off of that corner bend more. Which means grab the curve handles on either side of that point and move it up or down, until you have as much bend as you'd like. I added a little extra bend in my example image, but not a whole lot ( along the top edge of the curled corner ).
Tip: If I wanted my paper to look like it had a hard fold in it, then I would not move those extra control points I added, inward. I would leave them where they were originally added to the path.
Now we need to save our path, in case we need the shape later or decide to make some changes to it. Open the Paths palette if it isn't already open, and click the small arrow at the top-right. In the options menu choose 'Save Path'. Name it, and click OK.
5. Curling our paper corner (3)
Now we need to fill this path shape.
Press the D key to reset your Fore and Background swatches. Then within the Paths palette, click that small arrow at the top-right side again to open the options menu. Choose 'Fill Path'. Your shape should be filled with black now. Or, you can choose the Pen tool, and right-click (Mac: Ctrl-click) on the Path and choose the same command from the pop-up menu. Either way will work fine.
6. Adding Paper Characteristics (1)
This part is pretty simple also. Have a look at this example image and you'll see what you need to do to give the paper some color and shading.
Before applying the gradient, lock the layer's transparency. PS5+ users will click the 'Preserve Transparency' checkbox. You can choose whatever colors you like for your own paper, that's not an essential aspect here. Just make sure that your darkest color is at the top of the paper, and your 2 colors are in the same family, but different shades. I chose dark and light tan colors for mine. And try to make your colors very close in their shade. The color blend should be very subtle, not really blunt or too contrasting.
As the example shows, be sure you apply your gradient from the very top edge to the very bottom edge -- so we don't get an area of solid color
7. Adding Paper Characteristics (creating the missing corner)
Choose the Pen tool.Use the example image to the right as a guide, and create a selection just like the one shown. Basically, you're just selecting around the "imaginary" corner that's missing. Zoom right in on just that corner area to make this easier to do.
Once you have this Path shape created, create a new layer, move it below the 'paper' layer, then right-click (MAC: long-click) anywhere within the path area and choose the "Fill Path/Sub path" option from the pop-out menu. This will fill our shape with a solid color
And now for the magic move...
Select your paper shape, and while on the curled corner layer we just created, press Delete. This gives us the exact shape needed to fill-up the curled corner space.
Now fill this shape using the exact same linear gradient as you used for your paper... but... reverse the shades, so that the darker color is on the bottom of the selection, and the lighter shade is at the top edge. Which means apply the gradient from bottom to top. (see example image) And this will produce the reverse curl effect we want.
Tip: As a tweak to this part, you'll want to open the 'Hue & Saturation' filter, and lower the Saturation level about half, then raise the Lightness setting just a bit. We're trying to create a slightly faded effect for the underside of the paper. Creating the proper kind of Path shape: ^ Back To Step 2 If you're confused after reading this page, try using this Quick-View Image Sequence to help make things clearer.
Creating the proper kind of Path shape:
8. Fine-tuning the look - drop shadow
This part is pretty simple also. We're just going to add a few small details to enhance the effect a bit.
First up, a drop shadow.
9. Fine-tuning the look - creating some edge thickness and additional highlighting
We'll add a thin edge highlight to the curl, to help give some subtle depth to our paper. Duplicate the curled corner layer you created. Drag this duplicate layer below the original, and fill the shape with a solid white. Now click on the original curled corner layer and using the Move Tool and arrow keys, nudge this layer 2 pixels down.
Notice the thin edge highlight that appears along the top of the curled edge? It's very subtle, but it helps give the paper some visible thickness.
Additional highlighting: Pick the Airbrush now and then select the curled corner shape. Now with that selection active, on a new layer right above the curled corner layer, paint with white over top of just the curled tip of the paper's corner. Like it shows in this example image. Notice the highlight is only applied to the very tip of the curl; which makes it appear to really curl inward. Drop the Opacity to around 70%, and set the Blend Mode to Overlay. If the highlight looks too harsh, leave the selection on and Gaussian blur the paint a bit until it softens up. Then Deselect when you're done this.
10. Fine-tuning the look - curling what's on the paper
I'm sure a lot of you are hoping that I'll cover this, because some of you may not be very sure of how this is achieved. Well there's a simple method, and a not-so-simple method.
Simple: Once you create the picture or type that will appear on the paper, you just have to use the Edit > Transform > Distort tool to drag the bottom-right corner of your image/type until it looks like it's conforming to the bend in the paper. Honest! That's all there is to it!
Not-so-Simple: By duplicating the 'paper' layer, and filling the shape with a vertical Linear gradient, you can use the 'Displace' filter to force the image to be put on the paper, to curl. This method is best left to those experienced users, as it can be somewhat complex and confusing if you're not at all familiar with using the 'Displace' filter.
In most cases, the 'Simple' method can suffice. The only thing I'd suggest to help this part look better, is to add a Brightness & Contrast adjustment layer right above your image, and apply a linear gradient diagonally to it that is lighter on the top and darker on the bottom. Then clip/group this adjustment layer to the layer containing the picture or type that will be on the paper. This will help make the picture/type look like it's bending/curling more. You should only need to turn down the Brightness to -10 or so. ( See example image to the right. )
Ok well... there it is then. Hope that wasn't too painful!
