Replicating the look of a rubber stamp or other grunge effect in Photoshop is something that’s been done to death on the internet.
Unfortunately the results of existing tutorials are often very amateur and in no way actually reminiscent of an actual rubber stamp. So having had a few occasions where I’ve needed to experiment with this technique, I thought it’d be good to share my methods here.
The main difficulty is trying to mimic the randomness and unpredictability involved: the nicks in the rubber, the texture and density of the ink, the pressure with which the stamp is placed on the page, the little areas that the ink doesn’t reach, and the parts where the ink is slightly too heavy and fills in.
In truth there’s a lot of trial and error involved, and some specific manual editing for the most accurate replication. But playing with a few settings and layer modes you can actually achieve a fairly realistic effect. Here’s one technique which is by no means perfect, but certainly gives a good basis.
The main difficulty is trying to mimic the randomness and unpredictability involved…
Note. These steps are demonstrated in Adobe CS4 and assume a certain level of knowledge of Photoshop & Illustrator usage.
Create your graphic in Illustrator in single colour. Make sure that all white areas are punched out of the dark parts so the graphic is all one colour.
If you want to add a small amount of uneven texture to the lines at this stage you can use the Roughen effect (Effect – Distort & Transform – Roughen…) but be careful to keep the size very small and the detail very high (I’ve used 0.3% for size and 90% for detail).
Open a new greyscale document in Photoshop as big as you want the final stamp to appear and paste the graphic in as pixels on a new layer.
Give your stamp a Gaussian blur of around 2-3 pixels…
… and then use Unsharp Mask (Filter – Sharpen – Unsharp Mask) to give it hard edges again. This helps replicate the pressure applied to the stamp on the page; reducing the sharp edges and filling in and out slightly.
Find or take a decent resolution photo of a stone or concrete texture. The texture should be relatively fine, but preferably with some slightly larger imperfections as well. Paste this as a new layer over your stamp layer in Photoshop.
Use the stamp graphic to mask the stone texture by holding Command and clicking the thumbnail of the graphic, clicking the stone layer and selecting the ‘Add Layer Mask’ button on the bottom of the layer palette.
Duplicate this stone layer and hide the top version, then adjust the levels of the original to drastically boost the contrast. Pull the dark slider inwards to 130, leave the midtone slider at 1 and pull the light in to 200. This layer will form the outside edges of the stamp. Ctrl click the mask and select Apply Layer Mask.
Make the hidden stone layer visible: this will provide the detail inside the stamp where perhaps the ink was not in such close contact with the paper.
Command click the mask to select it, contract the selection by about 8-9 pixels and feather by about 4-5 pixels. Invert this new selection and fill with black on the mask.
Again using the Levels palette (or curves if you prefer), boost the contrast but a bit less than on the previous layer as we want more white areas here. I’ve pulled the darks in to 70 and the lights in to 220 which does the job quite nicely. Play around with the settings to achieve an effect you’re happy with and merge this layer with the duplicate beneath.
Now you can see the basis of the stamp effect. You could use duplicate this layer to a colour image, amend the colour as desired and set to Multiply on the layer mode. But to complete the job and give more control over the colouring I like to produce it as a mask on a solid colour layer as follows.
With the new merged layer active, click Select – Colour Range. Click the cursor on the darkest area of the stamp graphic, make ‘Fuzziness’ around 175-180 and hit OK.
Click the ‘Create New Fill or Adjustment Layer’ button on the Layers palette and select Solid Colour. Make the colour black, hit ok and hide all other layers (including background) and you’ll see that the white areas are now transparent and the stamp is set as a mask. Transfer this layer to another document as required and hey presto – your stamp is complete.
As I mentioned before, there is a lot of trial and error required to get this looking right. From the levels to the settings on the effects and the detail of the applied texture; if one thing isn’t working, try it differently! Another way to roughen the edges is, once the first Gaussian Blur is applied, to convert the image to bitmap then back to greyscale and apply a lighter blur to soften the dots before using Unsharp Mask to straighten the edges out. However, this technique involves flattening the graphic to the background, making selecting it difficult in future stages.
Here are some examples of stamps I’ve created for a couple of different jobs to show a variety of different, realistic effects that can be achieved. This includes work for Rayner Opticians which was completed while working for Mutual Ideas, by whom all rights are reserved.
I hope this is of some use – if you have another way of doing it I'd be very keen to hear!