PLA is the default first spool for good reasons: it prints at low temperature, needs no enclosure, warps very little, and comes in more colours and finishes than every other family combined. It is also the family where a cost or weight estimate is most likely to be silently wrong, because the blends are sold as PLA and do not behave like PLA on the scales.
What holds the family together
All seven grades here are polylactic acid with something added — a toughener, a sheen additive, a mineral matting filler, wood flour, a phosphor, chopped carbon fibre, or a reformulation for higher melt flow. The base polymer is the same, which is why the print temperatures cluster between roughly 190 and 235 °C, the bed sits between cold and 65 °C, and none of them needs an enclosure.
That shared chemistry also means they share the same ceiling. Every PLA on this site softens somewhere between 50 and 62 °C, which is inside the temperature a car interior reaches on a summer day. No PLA blend fixes that, whatever the marketing says about strength.
Where the family splits
Density. This is the axis that catches people out, because the grades are sold as PLA and do not weigh what PLA weighs. Base PLA sits near 1.24 g/cm³; matting fillers push a spool upward, the phosphor in a glow grade pushes it further still to as much as 1.40, and wood flour drags it the other way because it is lighter than the polymer it displaces. If a print came out heavier or lighter than the slicer promised, start here. Each member's own page carries its stored range and what it does to a cost estimate.
Abrasiveness. Plain, silk and high-speed PLA are gentle on a brass nozzle. Glow, carbon-filled and coarser matte grades are not: the phosphor in glow PLA in particular will visibly wear a brass nozzle within tens of hours. A hardened nozzle is cheap insurance, and a worn 0.4 mm that has become a 0.45 mm will quietly ruin your dimensional accuracy first.
Layer adhesion. Silk and matte grades both bond slightly worse than plain PLA. Silk parts in particular snap along layer lines more readily than they look like they should, which matters if a decorative part also has to hold something up.
Choosing within the family
For a functional part that stays indoors and cool, plain PLA or PLA+ and a higher wall count. For anything photographed, matte, because it hides layer lines and does not blow out under a light. For anything printed to be sanded, filled and painted, wood-filled, and use a 0.6 mm nozzle so partial clogs do not end the print at hour nine.
For anything that will be left in sunlight, none of them. PLA goes chalky and brittle under ultraviolet, and that is a chemistry problem the blends do not solve.
Printing the family
Bed adhesion is the same across all seven: a clean plate at 50 to 60 °C, no adhesive, and no enclosure. The failure mode people actually hit on PLA is not adhesion, it is heat creep — filament softening above the melt zone and jamming twenty minutes into a print — and it is far more common on an enclosed machine, because enclosures raise ambient temperature around the hotend heatsink. If your PLA jams reliably at the same point in every print and your printer is enclosed, open the door.
Cooling is the other family-wide rule, and it runs opposite to the styrenics. PLA wants the part-cooling fan at full speed for overhangs, bridges and top surfaces; the advice to turn cooling down that applies to ABS does not transfer here, and applying it to PLA produces sagging overhangs and pillowed tops.
Small parts are the exception worth knowing. A single small model gives each layer a second or two to cool, which is not enough, and the result is a slumped glossy mess at the top of a spire. Print four copies at once instead of tuning cooling — the fix is a minimum layer time, and printing more parts supplies it for free.