This is kind of informal (and random high end pieces will need random low end mats), but as a general rule of what key "material" synths exist.

These typically cross over so you'll need, say, a ~30 wood mat and ~30 metal mat to make a spear.

Spoiler: Hide
Wood
*3 logs = 1 lumber
1 - Maple
10 - Ash
16 - Elm
21 - Yew
25 - Walnut
32 - Oak
39 - Mahogany
45 - Rosewood
50* - Spruce

Metal (BSM/ARM)
1 - Bronze (3Copper + 1Tin)
16/13 - Iron (3Iron)
26 - Steel (2Iron + Bomb Ash)
38/36 - Mythril (3Mythril)
42 - Cobalt (2Cobalt + 1Iron)
50* - Darksteel

Metal (GSM)
*Noting whetstone tiers because those annoy me
1 - Copper (3Copper)
6 - Ragstone (2Ragstone)
13/14 - Tier 1 gems
*Sunstone/Danburite/Fluorite/Sphene/Malachite/Lapis Lazuli
14 - Brass (2Copper + 1Zinc)
20 - Mudstone
22-24 - Eye of (element)
23 - Silver (3Silver)
27-30 - T1 gem accessories
30 - Siltstone
32 - T2 gems
*Aquamarine/Amythyst/Garnet/Goshenite/Heliodor/Peridot
34 - Mythril (3Mythril)
37-40 - T2 gem accessories
40 - Basilisk
41 - T3 gems
*Amber/Zircon/Spinel/Turquoise/Tourmaline/Rubellite
42 - Electrum (4Electrum)
47-50 - T3 gem accessories
50* - Rose Gold, Astral Eye

Leather
1 - Animal Skin (Leather)
*1 - Animal Sinew
8 - Animal Hide (Hard Leather)
*~11: Beast Sinew
17 - Aldgoat
26 - Toad
*~26: Diremite Sinew
33 - Boar
*~33: Hippogryph Sinew (still used at 50)
38 - Peiste (you're still mostly using Boar)
41 - Raptor
*~43: Raptor Sinew
50* - Hippogryph, Coeurl

Cloth
1 - Hemp (Moko Grass)
12 - Cotton
23 - Dew/Velveteen (Diremite Webs + Cotton)
32 - Linen (Flax)
38 - Wool (Fleece)
43 - Felt (Fleece + Snurble Tufts + Natron)
50* - Twinthread (Crawler Cocoon)

Misc (stuff worth saving in general that isn't in a clean category, this needs expansion)
Wolf Fang, Red Coral, Spoken Blood