I have a shelf liner that has bumps on one side and is smooth on the other side. It is non-adhesive. Which side faces up, or what are pros/cons of each? It looks like this: 
Kitchens – Which side of a shelf liner faces up
kitchensshelving
Related Solutions
Heavy duty shelf brackets - supposed support 1000lbs (450kg !)
Shelf construction
If the shelf has its front open edge positioned such that at each four feet the cable would go up to a separate roof truss than I think that you have a workable system. Make sure that your 2x3's under the outer shelf edges are placed to that the nominal "3" inch dimension is vertical.
Hardware
Note that the lowest cost eyebolts, known as the "bent type eye bolt" are generally not recommended for lift and continuous tension applications. For this application it may be suggested to search out the drop forged type eye bolts as shown on the right below. These will cost more but they are actually specified for "lift" type applications.
If you do use the bent type, orient them so that the split end of the eye is up, as show above. Definitely use through-bolts rather than any type of screw-in eye.
I would use 5/16" diameter eye bolts or larger.
Connection points
Put the upper end of the cable through a threaded eye bolt that goes all the way through the side of the rafter truss and is secured in the far side with a washer and nut. Avoid the use of a screw eye type fastener. The eye bolt should be attached to the upper rafter part of the truss instead of the lower cross tie. When drilling the hole for the eye bolt position it in the upper part of the rafter as opposed to the lower portion.
Put the bottom end of the cable through an eye bolt that is long enough to go through the shelf material and the 2x3 and secure on the bottom with a washer and a nut.
Note that the orientation of the cable clamps is important, and it is always advisable to use two cable clamps for securing the cable.
Cable sizing
The size of cable is really dependent on the amount of load that you expect for the shelf. I would think that 3/16" diameter cable would be adequate for this application. The chart below will help to explain why I recommended 3/16" (assuming you use the 1x19 type of "stainless steel aircraft cable").
Related Topic
- How to remove a closet shelf & keep it intact
- How to take the hooks off of this shelf holder
- Easiest way to build an oddly-shaped shelf for cabinet above stove
- Hanging a shelf on a difficult wall
- Wooden shelf with flat brackets
- How to hang a shelf in an invisible manner
- Correct orientation for t-shaped shelf bracket to minimize stress on anchor bolts
- Identification of shelf brackets
Best Answer
The bumps face up to provide air flow.
This felicitates the complete and continuous drying of tableware which helps prevent the growth of bacteria, especially useful if you like to store your cups upside down.
There is a con to that type you have. Unlike others I've seen that are a sort of nylon web, yours is a solid sheet of plastic. If any water gets under it, it has no way to evaporate. You could put one sheet upside down to protect the cabinet, with another on top for the glassware (or just use one and be sure everything is relatively dry before stowing it).