Originally Posted by veggie_lover
Anyone know which is better, Reflexite or 3M Diamond Grade, ... Is the 3M harder to bend and stick on? I know SOLAS is the best, but it seems only available in white. ...
I read 3M's and other manufacturer's specification sheet PDF's several months ago before purchasing tape. The 3M Diamond Grade is the most reflective in a given color (more than the SOLAS product, much to my surprise). See LINK1 LINK2
White is the most reflective in any given product, followed by yellow. 3M apparently makes the Diamond Grade in a fluorescent yellow but I could not find a source.
I ended up getting the yellow Diamond grade from Hillas LINK
(ignore their picture, this is solid yellow tape, not alternating red and white). Now I have more than enough tape for marking the car door edges, bikes, etc. etc. The 1" wide will wrap (edge to midline of fender) around a large 26" fender (large = larger diameter) IF you put it on at an angle. I do not think it would stick well if you put a continuous strip along the length of the fender unless you made some small side cuts.
The specification sheets have all sorts of info on what materials it sticks to (e.g. they have a special tape for sticking to motor vehicle bumpers), what diameter it can wrap around, etc.
Example of the information on 3M Diamond Grade #983 at LINK
(unfortunately, the columns of numbers do not come out aligned here, see the link):
Table A. Typical Coefficient of Retroreflection (RA) for New Sheeting (cd/lux/m2).
Observation Angle1 0.2° 0.5°
Entrance Angle2 -4° 30° 45° -4° 30° 45°
983 Typical Values White 800 550 345 460 215 85
983 Typical Values Red 160 110 60 95 40 16
983 Typical Values Yellow 645 420 235 360 180 65
1 Observation Angle - the angle formed by the light beam striking the reflective surface and the light beam returning to the observer (from 800 feet, a motorist normally views a marking at approximately an 0.2° observation angle).
2 Entrance Angle - the angle formed by a light beam striking a surface at a point and a line perpendicular to the surface at the same point.
For more on 3M Diamond Grade conspicuity products: LINK1
3M Engineer Grade has much lower retroreflectivity: LINK
3M High Intensity Prismatic also lower retroreflectivity: LINK
3M SOLAS tape also lower than Diamond Grade: LINK
Reflexite also not a good as 3M Diamond grade: LINK
Bottom line: Get 3M Diamond Grade unless it will not conform to the curve and another product will.