number of IRCs

[KnightKobra49]

is it okay to use 4 international reply coupons to get chance to get it back when SAE is 6x4 size?

[ROB123]

is it okay to use 4 international reply coupons to get chance to get it back when SAE is 6x4 size?

I would say a maximum of 2 IRC's for a SAE sized 6x4 {thumb2}

[mharm2k6]

is it okay to use 4 international reply coupons to get chance to get it back when SAE is 6x4 size?

As ROB123 said, yes- according to some posts 2-3 can be enough for a 8x10 photo to be mailed so 4 seems like overkill. The only thing would be how far you'd be mailing it- as if mailing something from the US, it can cost more to mail farther international.
-mharm2k6