This is much easier than trying to add paint into the laser engraved portions after the fact.
This instructable assumes you have an image you wish to engrave and already know how to use the laser at TechShop.
Step 1: Attaching the transfer tape
In this example the wood we are using oak. Other woods such as alder are preferred but oak was chosen in this case. The transfer tape protective coating is peeled off and then the tape is applied to the piece. Start from the center and push out all the air bubbles. A good bond to the wood is essential for good results.
Step 2: Etch the wood
When this step is complete the paper should have been completely removed from the parts of the image that were etched by the laser.