Hope this isn't out of line, but I'm commenting just to bump this as I spent way too long looking for something like this thread and given the time of year, thought others might benefit as well.
I made one from a spare strip of turf from DDs PC. Ordered a $20 rubber from Amazon and used Gorilla Glue to hold it down. No problem with wear or lifting after 1 year of use. Total cost was $35
I made this one in Sept of 2017. I used duct tape instead of paint so my daughter could change the power line color / pattern periodically. I used the Tractor Supply stall mat. Looking back I should have trimmed it down to 3 ft wide instead of leaving it at 4 ft. That would cut down on carry weight.
I used a piece of 1x6 as the "rubber". I painted the top and sides white, then liquid nailed the bare wood bottom to the stall mat. It held up exceptionally well. Also using the 1 x lumber it raised the rubber up a little higher than a real rubber, which... In my opinion, is more similar to actual field conditions and the giant ledge dug in front of the rubber on every field.
The mat held up great until a month ago when it finally ripped during transport. Other than that, the only failure point was a small "trench" eventually dug out in the stall mat rubber where the toe drags.
That being said, I'm currently making another one as we speak.
I found this thread so useful! Made my daughter a pitching mat for Christmas. Used a heavy exercise mat and glued it to some green outdoor turf. I used 3M adhesive spray and coated both materials. Even used the spray to attach the base.
Add my attempt to the thread. Two 3 x 4 half inch thick recycled rubber mats from Rural King $19 ea. Pitching rubber $20. Little epoxy and paint. Think it will definitely serve its purpose.
Can someone tell me if this mat will work? I want a 9-ft one so may have to get 2.
Or if you have any other suggestions of mat to purchase, please let me know. Thanks!