Dotless LED Strip is dependant on a few factors. One considerable factor is the number of diodes or 'LEDchips" per metre and the second being the size of the Aluminium Profile.
The general rule is, a LED strip with diodes upwards of 240 LED's per metre will create a dotless glow in both shallow and deep aluminium profiles. Different LED Strip and aluminium profiles have different effects so we always recommend ordering samples from your local Havit Lighting Reseller to ensure the pairing is suitable to your application.