Just out of curiosity, what size crickets do you feed to your just hatched veileds?
Some people say pinhead all the way up to 1/4 inch. Seems like quite a difference to me.
Pinheads are a waste of money unless you are raising the smallest of species. Calyptratus babies are pretty big. You will be fine offering 7-10 day old crickets and hydei fruit flies. Switch to 1/4" after about a month.
At a month old the space between there eyes is about 1/4 inch, and that's what im currently feeding my near 1 month old panthers right now. I would agree with the space between there eyes as a general rule of thumb.
Fruit flies and the small crickets. The stores write small on the label of 1/8-1/4" crickets. Those will do you just fine. The flies move constantly around, while the crickets mostly hide on the bottom. A dual feeding illicits a feeding response, like no other. I highly recommend it. Especially for veils. My secret homemade recipe, handed down for generations .