As long as one follows
As long as one follows mixing instructions implicitly ( I even mix a minute or two longer than guidelines to ensure an even cure ), during the 'pour' I fill mold in layers, even if the mold has air vents, in order to ensure those air bubbles not getting trapped, pouring in graduated levels helps greatly, leaving each level 15 minutes or so before next level poured ensures 'what I call' the stickiness" adhering to last pour. Don't let your resin get into the 'sticky' stage (pours as slow as molasses in January) unless it is in an 'open face mold' ( a wide opening generally called the base). I like Art Resin a lot for it's even curing, quicker curing and demolding time (usually later the same day.) And its non toxicity is appealing as well.