I agree, chamois cloth works well and is less ugly than rubber shelf liner. Buy it cheaper at a car parts section, because people use it to polish/dry their cherished cars with.

Rather than using shelf liner try a natural shamois skin, the soft and absorbent animal skin sold for drying your car after a wash job.  I used it for years without it adversely affecting the finish on the dulcimer.

Totally agree with the slick slack advice.  Since I retired, my preference is shorts and blue jeans!!!  Thanks for the advice on straps advantages and disadvantages.  I have tried a strap and just did not like it that much.  I am seeing less movement using the advice of 'proper placement'.  I think I am going to stick with it for a while and see how much improvement I see.  

Great advice from great folks.

Thanks.

"If you habitually wear slick polyester slacks, then a shelf-liner is useful."

I think if you wear slick polyester slacks, it's probably best that you not venture out in public anyway. 

Actually @jmhundley, I personally think your original solution -- a "lap cover" if you will -- is a much safer option.  Seems like every time I get around a group which favors straps over good leg and dulcimer placement, or a cover, I see someone stand up without unstrapping, and the instrument hits the seat or ground.   Can't say I've ever seen an "unstrapped" player stand and drop their instrument.  I firmly believe that a "proper position" is more important that any artificial solution. 

The knees needs to be spread more than shoulder width apart; the first fret needs to be over the player's left knee (assuming right handed) while the bridge (more or less) needs to be tucked into the right hip, with the dulcimer diagonally across your lap.  You do not want your knees any closer together, and you don't want the instrument setting at right angles to your body, with more dulcimer hanging outside the knees than between them.  If you habitually wear slick polyester slacks, then a shelf-liner is useful.

I install an end button and use a regular guitar strap around my waist that ties around the headstock.

Thank you very much for the great advice.  This is exactly why I joined.  I needed help and you have really kept me from making a mistake storing the dulcimer with the shelf material.  I will start looking for a strap and getting used to it.  Sounds like a much better long term solution than mine.

Thanks again!!!!

As Dusty said, this is a common solution. When I first started playing dulcimer, I took this approach. It worked well. The warnings given already about not storing the material against the wood of the dulcimer are valid. Eventually, I did move on to using straps, which works better for me now. Don't rule them out, maybe it's something that will work for you later. If not, using the non-slip liner is just fine. Another case for straps is at festivals when people are moving around you. A strap helps secure your dulcimer in the event of an accidental hit. 

It's a great solution. But to confirm what Dusty warned on- do NOT store the rubber shelf material directly in contact with the wood. It WILL leave strange waffles patterns on your dulcimer over time. Not residue, but actually lightening the color of the wood so you can't just clean it off.

Hey @jmhundley, you've discovered a great solution that is, in fact, a pretty common one.  When I went to my first dulcimer festival there was someone there giving out pieces of the shelf liner for exactly that purpose.

My only advice is that when you store the items in your case, make sure they are not in permanent contact with the wood of the dulcimer.  They sometimes leave a mark on the dulcimer's finish if left in contact for too long, especially in a case with little air flow.

I was have problems with my dulcimer sliding/moving while I was playing.  I did not really want to use a strap if possible and I found a simple solution that so far has worked very well and I wanted to share it.  I cut 2 (12"/12")  pieces of rubber shelf liner.  I put one piece on each leg and it seems to have solved my sliding problem.  The two pieces helps keep the back of the dulcimer from getting scratched also while playing.  It also seems to be a little louder with the pieces lifting up the dulcimer.  The added benefit is I simply fold the two pieces and put them in my case when I store the dulcimer.  The extra padding helps keep the dulcimer from moving around in the case when storing it and toting it.  The link for the product I bought at Walmart is https://www.walmart.com/ip/EasyLiner-Select-Grip-20-in-x-6-ft-Shelf-Liner-Taupe/16486832.  I am sure other stores have the same or similar products that will work just as well.