Introduction: Creating Large Format Rubber Stamps

About: By day I work as a marketing & project manager, safety advisor, trainer and accident investigator but when I escape I like to make, mend and build anything with and from anything. Former tech teacher for 30 yr…

A local artist approached me to see if I could produce some rubber stamps so that she could mark her limited edition prints. However when one works with artists and you get talking ideas start to flow so we moved on to produce some large format laser engraved stamps of line drawings. This Instructable well 'tell the story' of this journey and the experiments to enable others to learn from what we discovered. We hope you find it interesting and helpful, we would welcome any feedback or suggestions  from others who have been down this road as well.

The artist is Jenny Beard and her website shows other pieces of her work. We would like to thank Jenny for the chance to develop something different and exciting. You can see more of our work on our website ATAmorecreations.

Step 1: Selecting the Image and Creating the Digital Design.

The first thing to do is to select a suitable image. In case of creating the initial stamps we were give a simple line drawing which we then transformed into a digital image using a simple drawing package. We like to work on a large format at this stage to enable the detail to be clearly seen, and it is easy to rescale later.
It is important to always check drawings carefully particularly if you are producing them for a client! Anything that is going to be made into a stamp needs to be MIRRORED otherwise when it is imprinted it be backwards! If there is text involved always double check spelling and get someone else to check it too!

I tend to keep a record in a Moleskine sketchbook of any work I do for a client. This is the first page of development for Jenny Beard. You can see her original sketches and the first impressions from the stamps.

Step 2: Using the Laser Cutter

NOTE:  I realise that not everyone has access to a laser cutter let alone owns their own. However there are many places and will continue to be more places where members of the public can access a laser cutter. Techshop and other open access schemes are growing, many schools, colleges and universities also will allow public access. There are also commercial access schemes as well. It will be rare to find someone who is going to allow free access but you never know. I am fortunate to own my own because I worked and save hard to enable me to purchase my own to develop my creative and design skills further. I offer a cutting service for a small fee to people who live near me. At the moment I am cutting a lot of quad copter parts for local enthusiasts, it does not take long for word to get out and it does not take long to start covering your costs either.

Safety: Laser cutters by the nature of the technology produce fumes, smoke and other contaminates. It is import ant to ensure that you are prepared for two major things, fumes and fire.

FIRE: burning with a laser is a fire risk so it is important to be prepared. Because my machine is in the house it is housed in a room with a smoke alarm and a good fire extinguisher. I also have a large extinguisher outside of the room just in case. NEVER leave a laser cutter working on its own!

FUMES: Extraction and ventilation are important. My machine vents outside through a filter system. There is little or no fumes in doors. 
Outside the fumes are diluted quickly and don't pose a risk. The HEPA and carbon filter system removes most of the material effectively.

As each machine is slightly different I am not going into the detail but rather giving general steps and tips which I have gather from experience. I you are going to be working with some else's equipment make sure that you appreciate that it is their machine at their expense and they will likely know more than you about it! There is nothing worse than having a Mr Know-it-all wanting to just take over. If you are prepared to watch, listen and learn then you will get a much better service.

My laser is a 50w 400x600mm CO2 laser by Thunder Laser systems. It is excellent and I am very happy with the service and support that I get from them. The picture here is of my machine in the factory while it was being built and tested!

Settings that I used are as follows:

cutting:  speed 6 power 90%
engraving: speed 200 power 40% scan gap 0.10 ramp engrave.

Step 3: Selecting the Rubber and Engraving

There are three types of laser rubber available as far as I am aware:
  1. standard which is a light grey colour
  2. low odour which is also light grey colour
  3. eco green rubber which is green in colour.
All are available in different thicknesses and up to A3 in size.

Standard laser rubber is easy to use but stinks of pot/weed when you engrave it!  Low odour still smells strongly even through the filters. Both of these produce a lot of dust so the machine requires a lot of regular cleaning.
The eco rubber as with all so called eco materials costs three times the price! However unlike a lot of other eco products it seems to me to be much better to use and produces better imprints.

In the UK there are few suppliers of these materials but it all seems to come from the same source. I now go tot he source for my supply.

If you buy these materials it is important to store them carefully to prevent damage. They are not cheap materials to use.

I have also tried some silicon rubber sheet which seems to work very well too but I am going to compare prices at some point. The only problem with the silicon is that the supplier couldn't advise me of its suitability for using in the laser or as a stamp.

The software that I use is called LaserGrav which is supplied by Thunder Laser. The image in the form of an image file (jpeg in this case) was imported into the software. The it is mirrored (dont forget this step) then INVERT the image so that you will removing the background and leaving the image to be printed.

Next input the correct settings for engraving the image and cutting the outline of the final stamp. These settings will depend on your machine or the machine you are using and the material you are using. This where you need to experiment on small pieces first and record the successes for later use. I make a note in a Moleskine and also keep a sample piece of the material with the settings written on them. These are then my reference for later projects.




Step 4: Mounting the Rubber on a Suitable Backing and Inking for the First Imprint

For the supports and backing for the small stamps I use some acrylic discs on the larger stamps I use thick MDF or thick acrylic. The rubber is attached to the backing with contact adhesive. Don't use double sided tape as this will affect the final print (it seems to leave an impression on the final imprint).

The supports need to be of a substantial size to prevent any flexing of the stamp during printing.  Mark the backing so it is easy to see which way up the image is.... ie which is the top!

The first loading of the stamp and creating the first imprint is exciting!  Take your time and record what you do so that you can use the best combination. You will see in the images below a sample strip with my notes. Try different combinations of backing (felt/rubber/thick card/paper) to get the best print.

Inks: there a pads as used in offices and liquid ink which needs to be spread on a hard smooth surface and the picked up with a printers roller before being loaded onto the stamp.

Step 5: Conclusion

I am sure that over time I will find better and different ways of printing and creating these stamps. I am awaiting some different rubber to try and would like to do some comparisons between them.

I hope that you have found this Instructable interesting. If you have any comments that would help me develop this project further then please post them.

If you dont have a laser cutter then please try the suggested locations which are given earlier.

Enjoy!

Step 6: Update....

Eco rubber seems to be more dense and slightly firmer than standard grades.
Standard grade stinks and makes a huge mess. (wont be using that again)!