Here's an attempt at a tutorial:
License Plate Tutorial
1) Open a new document of 550 pixels by 300 pixels at 300 Dots Per Inch resolution.
2) Fill BACKGROUND layer with any dark color (#000000 to #808080) or gradient (Tutorial uses linear gradient FG #788e9e To BG #263744).
3) Create a new 550 pixel by 300 pixel Transparent layer named "Plate."
4) Create a selection of 500 by 250 pixels using the Rectangle Select Tool with Rounded Corners set to a radius of 20.0 and Expand From Center selected.
5) Fill the 500 by 250 pixels selection on the Plate layer with linear gradient FG #E9E9E9 To BG #D2D2D2. Select None.
6) "Plate" layer selected - Filters - Noise - HSV Noise - Holdness = 10 - Hue = 10 - Saturation = 50 - Value = 50 (Values are subjective. Purpose is to create the illusion of metallic reflection seen on most plates.)
7) "Plate" layer selected - Script-Fu - Layer Effects - Drop Shadow - Color = #000000 - Opacity = 20 - Contour = Linear - Noise = 0 - Blending Mode = Multiply - Spread = 0 - Size = 3 - Offset Angle = 130 - Distance = 2 - Layer Knocks Out Drop Shadow selected.
8) "Plate" layer selected - Script-Fu - Layer Effects - Bevel And Emboss - Style = Inner Bevel - Depth = 10 - Direction = Up - Size = 0 - Soften = 0 - Angle = 130 - Altitude = 15 - Gloss Contour = Linear - Highlight Color = White (#FFFFFF) - Highlight Mode = Screen - Highlight Opacity =75 - Shadow Color = Black (#000000) - Shadow Mode = Multiply - Shadow Opacity = 43.
9) Create a New 550 by 350 pixels Transparent layer named "Bevel."
10) Alpha-To-Selection on the "Plate" layer.
11) Select the "Bevel" layer. Shrink the selection by 5 pixels and bucket fill the selection with Black (#000000).
12) Shrink the selection by 10 pixels and press Delete OR Edit - Clear. Select None.
13) "Bevel" layer - Set Opacity to 0.
14) "Bevel" layer selected - Script-Fu - Layer Effects - Outer Glow - Color = Black (#000000) - Opacity = 10 - Contour = Half Round - Noise = 0 - Blending Mode = Normal - Spread = 0 - Size = 5.
15) "Bevel layer selected - Script-Fu - Layer Effects - Bevel And Emboss - Style = Inner Bevel - Depth = 35 - Direction = Up - Size = 8 - Soften = 2 - Angle = 130 - Altitude = 15 - Gloss Contour = Half Round - Highlight Color = White (#FFFFFF) - Highlight Mode = Normal - Highlight Opacity = 40 - Shadow Mode = Multiply = Shadow Opacity = 5 - Shadow Contour = Half Round.
16) Text Tool - Color Of Choice (#404D5E used for Tutorial) - Type Text at Font Size Of Choice (135 pixels used for Tutorial). Layer - Autocrop Layer - Alignment Tool - Align Relative To Image - Align Center Of Target - Align Middle Of Target.
17) (OPTIONAL) Text Layer - Move Tool - Tool Toggle = Move The Active Layer - Move the Text layer down 25 pixels. (This step is necessary if you intend on adding State name text in Optional step #22)
18) Create a New Layer named "Text Bevel" under the Text layer.
19) Alpha To Selection the Text layer.
20) Select the "Text Bevel" layer. Grow the selection by 5 pixels. Fill the selection with Color Of Choice. (Tutorial uses #829DBF). Set the Opacity of the "Text Bevel" layer to 0.
21) "Text Bevel" layer selected - Script-Fu - Layer Effects - Bevel And Emboss - Style = Inner Bevel - Depth = 35 - Direction = Up - Size = 8 - Soften = 2 - Angle = 130 - Altitude = 15 - Gloss Contour = Half Round - Highlight Color = White (#FFFFFF) - Highlight Mode = Normal - Highlight Opacity = 100 - Shadow Mode = Multiply = Shadow Opacity = 10 - Shadow Contour = Half Round.
22) (OPTIONAL) Text Tool - Type State name in 50 point Mistral Color #C02922 or other font, color and size of choice.
23) (OPTIONAL) Layer - New From Visible - View - Show Grid - View - Snap To Grid - Image - Configure Grid - Spacing Width = 25 - Spacing Height = 25.
24) (OPTIONAL) Ellipse Select Tool - Select and Delete four 25 pixel circular selections (75,75) (75,250) (450,75) (450,250) to create the screw holes.
25) You can also create registration stickers or use grunge brushes to create dirt or grime or use rust textures to create various effects. The possible results are virtually limitless.
![Image](http://www.gimpchat.com/files/269_Plate%20Tutorial.png)
If any part of this is confusing please let me know as I rarely do tutorials.