Scale Rope??

I would think that except for maybe resist decals (like those used for rivets) there really isn't anything on the market that would work.  Depending on the scale, options might include EZ Line fine which scales at around 3/4 in diameter  in HO, very lightweight fishing line or perhaps threads from coarse, unraveled sisal rope (yeah, we modellers do some mighty strange stuff).  I've seen photo-etched ropes for model ship builders, but don't know sizes.

Rick G.

Scale Rope?

Dear Mark,

Instead of decals trying to look like scale rope, how about actual scale rope?
Try the ship-modelling range from Artesania, available in VIC from Brunel Hobbies

http://www.brunelhobbies.com.au/Artesania/artesania.htm

The Artesania rope
(named as "cotton thread", part #s 8801 thru 8815, covers various colors and sizes)

EG https://www.artesanialatina.net/en/accessories-for-ship-modelling/2342-cotton-thread-black-015-mm-40-m.html

is available down to 0.15mm dia, with the next step up being 0.26mm. This is well small-enough to pass muster for most HO rigging, wound-rope, and logging-winch detailing. (I've used the smallest stuff to wind a "over the arm" rope bundle with a scale eyelet in the "leading end", to hang off the bulkhead of a HOn30 railtruck).

and the Artesania rope takes "stains" of Tamiya XF-series acrylics and "Oil Wash" (Black India-ink + "IsoCol" ispropyl alcohol) beautifully. For "shiny" steel rope, use XF19 "sky grey" + oil-wash as a base, then use graphite dust to burnish a sheen into it...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

PS if still "not good enough", you could try the ultra-thin metal "rope" available for picture-hanging and "craft" missions from SpotLight. It's need painting, but will "coil", "rig", and "knot" nicely with tweezers as the metal "holds the shape" required...

https://www.spotlightstores.com/craft-hobbies/beads-jewellery/beading-tools-accessories/wire-thread/shamrock-craft-beading-wire/p/BP80121395002
(Hint: "32 gauge" is 0.2mm)

Another option

Another option I use sometimes is to use metal rope...

Find yourself a corded mouse and cut the cord. Gently slice open the outside insulation, grab one of the inside wires and open the insulation on it. You can unwind, remove as many strands as you need, and rewind the wire into your rope. Give it a quick paint and you are good to go. The individual strands are hair fine so you can twist them into as thick or as thin a diameter rope as you want. I will warn you though, individually the wires are fragile.

Hie ye to a fly-fishing shop,

Hie ye to a fly-fishing shop, and get yourself some fly tying thread... and a bobbin, too, while you're at it. Fly tying thread comes in a myriad of colors, and in MUCH finer sizes than you find in a sewing department. The bobbin will help you control it while you're adding it to your loads.

I put the tarp over the cables on this N scale turbine load, but you can see a bit of them peeking out at the bottom. The tarp is facial tissue draped over the form and painted with mod podge, folded and arranged while wet, then painted and dry-brushed after drying,