Go to the hardware store. Look in the Isle with tape, and adhesives. There is some grip tape that is used for putting on steps and ramps. It is black and has a sandpaper finish. It is about 1 1/2" wide. You can trace the shape of  the raised portion of the grip using a piece of paper and rubbing a pencil over it. Then use that as a stencil to cut out the grip tape. you should be able to make 4 or 5 sets for about $5.00. I have used it on competition, and tactical guns. It is inexpensive,durable, removeable, and provides positive grip.

HEY! We're suppose to ask you if they are in stock!

3M makes adhesive backed grip tape.   Get a sharpie and draw out the shape you want and then cut it out.   Take alcohol and swab area where you wish to install it.  Once dry  peel and stick.
You can make custom shapes and sizes that fit your desire.

Home Depot, Lowes, and Ace Hardware all have the tape.   Much cheaper and generally better quality than pre packaged.   I make grip panels for lots of guys on my squad.  They always ask me to make them newones before quals. Of course no one wants them the same.  Everyone is different.

www.mle-shootingsports.com/

i got my trugrip from here,,,,, Mike sent me my order, and for free included a new mousepad, some lube, a notepad, all for free!!  Great guy, and sent my package priority mail to boot at no extra charge!!

www.ericwesselman.com/store/Glock.html