# Soft Black V4 **URL:** \ **Category:** Form 2\ **Created:** [November 23, 2018, 12:37pm UTC](https://forum.formlabs.com/t/soft-black-v4/21309 "2018-11-23T12:37:43Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![wunwinglow](https://avatars.discourse-cdn.com/v4/letter/w/ba8739/32.png) [@wunwinglow](https://forum.formlabs.com/u/wunwinglow)\ **Post date:** [November 23, 2018, 12:37pm UTC](https://forum.formlabs.com/t/soft-black-v4/21309/1 "2018-11-23T12:37:43Z")
I just wondered if there had been any progress on a solution to the Black v4 not curing properly in FormLabs 2 machines. Or if there ever will be… Tim ---
**Author:** ![tonberryhunter](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/tonberryhunter/32/11836_2.png) [@tonberryhunter](https://forum.formlabs.com/u/tonberryhunter)\ **Post date:** [November 26, 2018, 3:12am UTC](https://forum.formlabs.com/t/soft-black-v4/21309/2 "2018-11-26T03:12:36Z")
I stopped using my black V4 after wasting time and energy on rubbery or soft prints that then deformed after a typical post cure cycle. Formlabs like turn the other way and either throw free stuff at you til you stop complaining or act as if they had no knowledge of the material or part failure. Grey resin and clear seem to cure the best so far. Tough resin stays rubbery like the black. ---
**Author:** ![wunwinglow](https://avatars.discourse-cdn.com/v4/letter/w/ba8739/32.png) [@wunwinglow](https://forum.formlabs.com/u/wunwinglow)\ **Post date:** [November 26, 2018, 9:56am UTC](https://forum.formlabs.com/t/soft-black-v4/21309/3 "2018-11-26T09:56:23Z")
Pretty much my experience too… ---
**Author:** ![P3D](https://avatars.discourse-cdn.com/v4/letter/p/2acd7d/32.png) [@P3D](https://forum.formlabs.com/u/P3D)\ **Post date:** [November 26, 2018, 11:04am UTC](https://forum.formlabs.com/t/soft-black-v4/21309/4 "2018-11-26T11:04:48Z")
We didn’t even start using black for this reason. However, we didn’t experience any rubbery parts with tough. We had sticky surfaces when not properly washed, but the parts were quite stiff when cured properly, even before we got our Form Cure. ---
**Author:** ![tonberryhunter](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/tonberryhunter/32/11836_2.png) [@tonberryhunter](https://forum.formlabs.com/u/tonberryhunter)\ **Post date:** [November 26, 2018, 3:10pm UTC](https://forum.formlabs.com/t/soft-black-v4/21309/5 "2018-11-26T15:10:55Z")
My mileage with tough might be quite different because I was dealing with assemblies that had 2mm or sometimes less wall thicknesses. Its sold as “ABS” and feels similar to a less durable nylon. ABS is far more rigid and elastic. Even standard grey preforms better for my end use parts. Yes tough is less brittle but it exhibits an undercured property similar to the black. Parts would not spring back nor did they every really seem to fully cure even after hours under UV exposure. ---
**Author:** ![P3D](https://avatars.discourse-cdn.com/v4/letter/p/2acd7d/32.png) [@P3D](https://forum.formlabs.com/u/P3D)\ **Post date:** [November 26, 2018, 3:24pm UTC](https://forum.formlabs.com/t/soft-black-v4/21309/6 "2018-11-26T15:24:12Z")
Yes, tough doesn’t like low wall thicknesses (all sorts of warping can ensue), but as for not fully curing, what kind of cure box do you use? ---
**Author:** ![tonberryhunter](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/tonberryhunter/32/11836_2.png) [@tonberryhunter](https://forum.formlabs.com/u/tonberryhunter)\ **Post date:** [November 26, 2018, 3:51pm UTC](https://forum.formlabs.com/t/soft-black-v4/21309/7 "2018-11-26T15:51:43Z")
I built a cabinet with UV led light strip lining the inside and an acrylic motorized turntable. It generates its own heat and I often post cure with a space heater to help speed things up. The tough parts arent tacky at all they just never feel hard enough. When parts bend they dont spring back to shape. Even when out in direct sunlight Im still not impressed. Sure parts are stronger but nothing like ABS. ---
**Author:** ![system](https://us1.discourse-cdn.com/flex025/uploads/formlabs/original/3X/5/b/5bc2bdf993ff27c2e0eecab5010b25626fbb327a.png) [@system](https://forum.formlabs.com/u/system)\ **Post date:** [December 3, 2018, 3:51pm UTC](https://forum.formlabs.com/t/soft-black-v4/21309/8 "2018-12-03T15:51:54Z")
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