Hello! This is one of the first strings that isn’t really made for modern 1a that i’m reviewing. If you ever had the question “does this string work for 1A” but never wanted to torture yourself, don’t fear. I did it for you. 
YoYoFactory Retro Response String || F (49/100)
I really did have faith in this. It was really soft, felt good, and tech tricks were perfectly ok. When I felt it was broken in, I went for some slack tricks, and it did not feel very solid. I guess people better than me could make it work, but I couldn’t. Then I went for whips and oh my lord. First zero of this review page. It just wouldn’t go. I started laughing out loud, it was so very funny. I kept going for 1.5 whips and cackling when the string just wouldn’t move at all. I got used to it after the HOUR, but it’s still so funny. Tension hold was surprisingly good, and the same was with the durability. This string held sturdy really well. I have no clue what the material is, but if it’s 100% poly, I have no idea why this can’t be used for other modern strings. Also it slipped so much and basically made my monarch feel padless. Hated it. This is going in the string ball. Stats below.
Durability 30 min (4)
Durability 1 hr (4) looks like i gnawed on it tho
Personal Thickness Feel (1) please never do this to me again
Whip Feel Break-In (0) HAHSHSHA
Whip Feel 1 hr (1) this is so funny but i got the hang of it
Slack Feel Break-In (2) floppy and sad
Slack Feel 1 hr (2)
Tension Hold over 1 hour overall (4.5) actually really good
Softness during break-in (5) GOOD
Overall consistency over 1 hour (1) nothing. i am gambling.
Total: 24.5 x 2 = 49, 49 = F graded based on letter system (A: 100-90, B: 89-80, C: 79-70, D: 69-60, F: 60<)
I’ve been meaning to find a monarch replacement for my reviews so I don’t have to use it every time, so if you have any 4.5mm gap yo-yos with a similar gap shape to the monarch (which i’m assuming contributes to binds), please comment. thanks 